Vulnerability-Lookup

RHSA-2026:57994

Vulnerability from csaf_redhat - Published: 2026-08-21 01:48 - Updated: 2026-08-28 12:39

Summary

Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

Severity

Low

Notes

Topic: An update for Red Hat Hardened Images RPMs is now available.

Details: This update includes the following RPMs: ruby3.4: * ruby3.4-3.4.10-31.6.hum1 (aarch64, x86_64) * ruby3.4-bundled-gems-3.4.10-31.6.hum1 (aarch64, x86_64) * ruby3.4-default-gems-3.4.10-31.6.hum1 (noarch) * ruby3.4-devel-3.4.10-31.6.hum1 (aarch64, x86_64) * ruby3.4-doc-3.4.10-31.6.hum1 (noarch) * ruby3.4-libs-3.4.10-31.6.hum1 (aarch64, x86_64) * rubygem3.4-bigdecimal-3.1.8-31.6.hum1 (aarch64, x86_64) * rubygem3.4-bundler-2.6.9-31.6.hum1 (noarch) * rubygem3.4-devel-3.6.9-31.6.hum1 (noarch) * rubygem3.4-io-console-0.8.1-31.6.hum1 (aarch64, x86_64) * rubygem3.4-irb-1.14.3-31.6.hum1 (noarch) * rubygem3.4-json-2.9.1-31.6.hum1 (aarch64, x86_64) * rubygem3.4-minitest-5.25.4-31.6.hum1 (noarch) * rubygem3.4-power_assert-2.0.5-31.6.hum1 (noarch) * rubygem3.4-psych-5.2.2-31.6.hum1 (aarch64, x86_64) * rubygem3.4-racc-1.8.1-31.6.hum1 (aarch64, x86_64) * rubygem3.4-rake-13.2.1-31.6.hum1 (noarch) * rubygem3.4-rbs-3.8.0-31.6.hum1 (aarch64, x86_64) * rubygem3.4-rdoc-6.14.0-31.6.hum1 (noarch) * rubygem3.4-rexml-3.4.4-31.6.hum1 (noarch) * rubygem3.4-rss-0.3.1-31.6.hum1 (noarch) * rubygem3.4-rubygems-3.6.9-31.6.hum1 (noarch) * rubygem3.4-test-unit-3.6.7-31.6.hum1 (noarch) * rubygem3.4-typeprof-0.30.1-31.6.hum1 (noarch) * ruby3.4-3.4.10-31.6.hum1.src (src)

Terms of Use: This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original.

CVE-2026-54876

A flaw was found in OpenSSL. A malicious TLS (Transport Layer Security) server can exploit this vulnerability by sending a specially crafted OCSP (Online Certificate Status Protocol) response during the X.509 certificate chain verification process. This can lead to a memory leak in client applications that have enabled OCSP response checking. Repeated connections to a malicious server could exhaust the client's memory, ultimately resulting in a Denial of Service (DoS).

3.7 (Low)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

CWE-772 - Missing Release of Resource after Effective Lifetime

Affected products

Fixed 4 products

Product	Version	Remediation
Unresolved product id: Red Hat Hardened Images:ruby3-4-main@aarch64	—	Vendor Fix fix
Unresolved product id: Red Hat Hardened Images:ruby3-4-main@noarch	—	Vendor Fix fix
Unresolved product id: Red Hat Hardened Images:ruby3-4-main@src	—	Vendor Fix fix
Unresolved product id: Red Hat Hardened Images:ruby3-4-main@x86_64	—	Vendor Fix fix

Threats

Impact Low

References

12 references

URL	Category
https://access.redhat.com/errata/RHSA-2026:57994	self
https://images.redhat.com/	external
https://access.redhat.com/security/cve/CVE-2026-54876	external
https://access.redhat.com/security/updates/classi…	external
https://security.access.redhat.com/data/csaf/v2/a…	self
https://access.redhat.com/security/cve/CVE-2026-54876	self
https://bugzilla.redhat.com/show_bug.cgi?id=2511600	external
https://www.cve.org/CVERecord?id=CVE-2026-54876	external
https://nvd.nist.gov/vuln/detail/CVE-2026-54876	external
https://github.com/openssl/openssl/commit/155b5fe…	external
https://github.com/openssl/openssl/commit/d8c5104…	external
https://openssl-library.org/news/secadv/20260805.txt	external

JSON

To clipboard

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  "vulnerabilities": [
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      "cve": "CVE-2026-54876",
      "cwe": {
        "id": "CWE-772",
        "name": "Missing Release of Resource after Effective Lifetime"
      },
      "discovery_date": "2026-08-05T15:21:19.015952+00:00",
      "ids": [
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          "system_name": "Red Hat Bugzilla ID",
          "text": "2511600"
        }
      ],
      "notes": [
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          "category": "description",
          "text": "A flaw was found in OpenSSL. A malicious TLS (Transport Layer Security) server can exploit this vulnerability by sending a specially crafted OCSP (Online Certificate Status Protocol) response during the X.509 certificate chain verification process. This can lead to a memory leak in client applications that have enabled OCSP response checking. Repeated connections to a malicious server could exhaust the client\u0027s memory, ultimately resulting in a Denial of Service (DoS).",
          "title": "Vulnerability description"
        },
        {
          "category": "summary",
          "text": "openssl: OpenSSL: Memory leak leads to Denial of Service in OCSP response checking",
          "title": "Vulnerability summary"
        },
        {
          "category": "general",
          "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product\u0027s status, and are included for informational purposes to better understand the severity of this vulnerability.",
          "title": "CVSS score applicability"
        }
      ],
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          "Red Hat Hardened Images:ruby3-4-main@noarch",
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          "Red Hat Hardened Images:ruby3-4-main@x86_64"
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        {
          "category": "external",
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          "date": "2026-08-21T01:48:23+00:00",
          "details": "For details on how to apply this update, which includes the changes described in this advisory, refer to:\nhttps://images.redhat.com/",
          "product_ids": [
            "Red Hat Hardened Images:ruby3-4-main@aarch64",
            "Red Hat Hardened Images:ruby3-4-main@noarch",
            "Red Hat Hardened Images:ruby3-4-main@src",
            "Red Hat Hardened Images:ruby3-4-main@x86_64"
          ],
          "restart_required": {
            "category": "none"
          },
          "url": "https://access.redhat.com/errata/RHSA-2026:57994"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 3.7,
            "baseSeverity": "LOW",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
            "version": "3.1"
          },
          "products": [
            "Red Hat Hardened Images:ruby3-4-main@aarch64",
            "Red Hat Hardened Images:ruby3-4-main@noarch",
            "Red Hat Hardened Images:ruby3-4-main@src",
            "Red Hat Hardened Images:ruby3-4-main@x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Low"
        }
      ],
      "title": "openssl: OpenSSL: Memory leak leads to Denial of Service in OCSP response checking"
    }
  ]
}

CVE-2026-54876 (GCVE-0-2026-54876)

Vulnerability from cvelistv5 – Published: 2026-08-05 13:59 – Updated: 2026-08-05 19:31

Title

Client-Side Memory Leak in OCSP Response Checking

Summary

Issue summary: A malicious TLS server can cause a memory leak in a TLS client that has enabled OCSP response checking by sending an OCSP response that contains no single response entries. Impact summary: An attacker can leak an attacker-tunable amount of memory per TLS handshake in a victim client application. A long-running client that repeatedly connects to a malicious server can have its memory exhausted, resulting in a Denial of Service. CWE: CWE-401: Missing Release of Memory after Effective Lifetime Description: The affected function is called during X.509 certificate chain verification when OCSP response checking is enabled with the X509_V_FLAG_OCSP_RESP_CHECK or X509_V_FLAG_OCSP_RESP_CHECK_ALL verification flags, for example when a TLS client verifies an OCSP response stapled into the TLS handshake by the server. When the received BasicOCSPResponse contains an empty SEQUENCE OF SingleResponse, which is permitted on the wire and accepted by the OpenSSL decoder, the OCSP_BASICRESP structure allocated by OCSP_response_get1_basic() was not freed because an early return bypassed the cleanup code at the end of the function. The amount of memory leaked per handshake can be amplified by the attacker by padding the certs field of the BasicOCSPResponse with bogus certificates, which are parsed and stored in the leaked structure before the empty response check triggers the early return. A long-running TLS client that repeatedly connects to a malicious server can have its memory exhausted over time. OCSP response checking is not enabled by default. Only client applications that explicitly enable the OCSP response check verification flags are affected. FIPS impact: no The FIPS modules in 4.0 and 3.6 are not affected by this issue as the affected code is outside the OpenSSL FIPS module boundary.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-05 19:31 UTC

CWE

CWE-401 - Missing Release of Memory after Effective Lifetime

Assigner

openssl mitre root

References

4 references

URL	Tags
https://openssl-library.org/news/secadv/20260805.txt	vendor-advisory
https://github.com/openssl/openssl/commit/d8c5104…	patch
https://github.com/openssl/openssl/commit/155b5fe…	patch
http://www.openwall.com/lists/oss-security/2026/08/05/8

Impacted products

1 product

Vendor	Product	Version
OpenSSL	OpenSSL	Affected: 4.0.0 , < 4.0.2 (semver) Affected: 3.6.0 , < 3.6.4 (semver)

Date Public

2026-08-05 11:43

Credits

Bhabani Sankar Das Zhenzhe Shao Mounir Idrassi

Show details on NVD website

JSON

To clipboard

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                "role": "CISA Coordinator",
                "timestamp": "2026-08-05T19:31:37.065781Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-05T19:31:51.591Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "OpenSSL",
          "vendor": "OpenSSL",
          "versions": [
            {
              "lessThan": "4.0.2",
              "status": "affected",
              "version": "4.0.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.6.4",
              "status": "affected",
              "version": "3.6.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "Bhabani Sankar Das"
        },
        {
          "lang": "en",
          "type": "reporter",
          "value": "Zhenzhe Shao"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Mounir Idrassi"
        }
      ],
      "datePublic": "2026-08-05T11:43:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Issue summary: A malicious TLS server can cause a memory leak in a TLS\u003cbr\u003eclient that has enabled OCSP response checking by sending an OCSP\u003cbr\u003eresponse that contains no single response entries.\u003cbr\u003e\u003cbr\u003eImpact summary: An attacker can leak an attacker-tunable amount of memory\u003cbr\u003eper TLS handshake in a victim client application. A long-running client\u003cbr\u003ethat repeatedly connects to a malicious server can have its memory\u003cbr\u003eexhausted, resulting in a Denial of Service.\u003cbr\u003e\u003cbr\u003eCWE: CWE-401: Missing Release of Memory after Effective Lifetime\u003cbr\u003e\u003cbr\u003eDescription: The affected function is called during X.509 certificate\u003cbr\u003echain verification when OCSP response checking is enabled\u003cbr\u003ewith the X509_V_FLAG_OCSP_RESP_CHECK or X509_V_FLAG_OCSP_RESP_CHECK_ALL\u003cbr\u003everification flags, for example when a TLS client verifies an OCSP\u003cbr\u003eresponse stapled into the TLS handshake by the server.\u003cbr\u003e\u003cbr\u003eWhen the received BasicOCSPResponse contains an empty SEQUENCE OF\u003cbr\u003eSingleResponse, which is permitted on the wire and accepted by the\u003cbr\u003eOpenSSL decoder, the OCSP_BASICRESP structure allocated by\u003cbr\u003eOCSP_response_get1_basic() was not freed because an early return\u003cbr\u003ebypassed the cleanup code at the end of the function.\u003cbr\u003e\u003cbr\u003eThe amount of memory leaked per handshake can be amplified by the\u003cbr\u003eattacker by padding the certs field of the BasicOCSPResponse with\u003cbr\u003ebogus certificates, which are parsed and stored in the leaked\u003cbr\u003estructure before the empty response check triggers the early return.\u003cbr\u003eA long-running TLS client that repeatedly connects to a malicious\u003cbr\u003eserver can have its memory exhausted over time.\u003cbr\u003e\u003cbr\u003eOCSP response checking is not enabled by default. Only client\u003cbr\u003eapplications that explicitly enable the OCSP response check\u003cbr\u003everification flags are affected.\u003cbr\u003e\u003cbr\u003eFIPS impact: no\u003cbr\u003e\u003cbr\u003eThe FIPS modules in 4.0 and 3.6 are not affected by this issue as the\u003cbr\u003eaffected code is outside the OpenSSL FIPS module boundary."
            }
          ],
          "value": "Issue summary: A malicious TLS server can cause a memory leak in a TLS\nclient that has enabled OCSP response checking by sending an OCSP\nresponse that contains no single response entries.\n\nImpact summary: An attacker can leak an attacker-tunable amount of memory\nper TLS handshake in a victim client application. A long-running client\nthat repeatedly connects to a malicious server can have its memory\nexhausted, resulting in a Denial of Service.\n\nCWE: CWE-401: Missing Release of Memory after Effective Lifetime\n\nDescription: The affected function is called during X.509 certificate\nchain verification when OCSP response checking is enabled\nwith the X509_V_FLAG_OCSP_RESP_CHECK or X509_V_FLAG_OCSP_RESP_CHECK_ALL\nverification flags, for example when a TLS client verifies an OCSP\nresponse stapled into the TLS handshake by the server.\n\nWhen the received BasicOCSPResponse contains an empty SEQUENCE OF\nSingleResponse, which is permitted on the wire and accepted by the\nOpenSSL decoder, the OCSP_BASICRESP structure allocated by\nOCSP_response_get1_basic() was not freed because an early return\nbypassed the cleanup code at the end of the function.\n\nThe amount of memory leaked per handshake can be amplified by the\nattacker by padding the certs field of the BasicOCSPResponse with\nbogus certificates, which are parsed and stored in the leaked\nstructure before the empty response check triggers the early return.\nA long-running TLS client that repeatedly connects to a malicious\nserver can have its memory exhausted over time.\n\nOCSP response checking is not enabled by default. Only client\napplications that explicitly enable the OCSP response check\nverification flags are affected.\n\nFIPS impact: no\n\nThe FIPS modules in 4.0 and 3.6 are not affected by this issue as the\naffected code is outside the OpenSSL FIPS module boundary."
        }
      ],
      "metrics": [
        {
          "format": "other",
          "other": {
            "content": {
              "text": "Low"
            },
            "type": "https://openssl-library.org/policies/general/security-policy/"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-401",
              "description": "CWE-401 Missing Release of Memory after Effective Lifetime",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T13:59:36.466Z",
        "orgId": "3a12439a-ef3a-4c79-92e6-6081a721f1e5",
        "shortName": "openssl"
      },
      "references": [
        {
          "name": "OpenSSL Advisory",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://openssl-library.org/news/secadv/20260805.txt"
        },
        {
          "name": "4.0.2 git commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/openssl/openssl/commit/d8c51048ac037a21bae0f41cad7a3920dc7f3638"
        },
        {
          "name": "3.6.4 git commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/openssl/openssl/commit/155b5fe0f93365e6df1c56ee3606b121080c6c12"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Client-Side Memory Leak in OCSP Response Checking",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "3a12439a-ef3a-4c79-92e6-6081a721f1e5",
    "assignerShortName": "openssl",
    "cveId": "CVE-2026-54876",
    "datePublished": "2026-08-05T13:59:36.466Z",
    "dateReserved": "2026-06-16T10:18:08.636Z",
    "dateUpdated": "2026-08-05T19:31:51.591Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

RHSA-2026:57994

CVE-2026-54876 (GCVE-0-2026-54876)

Tags

Sightings

Nomenclature