Vulnerability-Lookup

RHSA-2026:54070

Vulnerability from csaf_redhat - Published: 2026-08-12 02:50 - Updated: 2026-09-06 04:58

Summary

Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update

Severity

Moderate

Notes

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

Details: This update includes the following RPMs: libssh2: * libssh2-1.11.1-10.4.hum1 (aarch64, x86_64) * libssh2-devel-1.11.1-10.4.hum1 (aarch64, x86_64) * libssh2-docs-1.11.1-10.4.hum1 (noarch) * libssh2-1.11.1-10.4.hum1.src (src) Security Fix(es): libssh2: * CVE-2026-58050

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-2026-58050

A flaw in libssh2 allows a malicious SSH server to trigger a memory overflow by sending a manipulated attribute count. This can cause the connecting client to crash or allow unauthorized code execution.

7.0 (High)


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

CWE-787 - Out-of-bounds Write

Affected products

Fixed 4 products

Product	Version	Remediation
Unresolved product id: Red Hat Hardened Images:libssh2-main@aarch64	—	Vendor Fix fix Workaround
Unresolved product id: Red Hat Hardened Images:libssh2-main@noarch	—	Vendor Fix fix Workaround
Unresolved product id: Red Hat Hardened Images:libssh2-main@src	—	Vendor Fix fix Workaround
Unresolved product id: Red Hat Hardened Images:libssh2-main@x86_64	—	Vendor Fix fix Workaround

Threats

Impact Moderate

References

12 references

URL	Category
https://access.redhat.com/errata/RHSA-2026:54070	self
https://access.redhat.com/security/cve/CVE-2026-58050	external
https://access.redhat.com/security/updates/classi…	external
https://images.redhat.com/	external
https://security.access.redhat.com/data/csaf/v2/a…	self
https://access.redhat.com/security/cve/CVE-2026-58050	self
https://bugzilla.redhat.com/show_bug.cgi?id=2493955	external
https://www.cve.org/CVERecord?id=CVE-2026-58050	external
https://nvd.nist.gov/vuln/detail/CVE-2026-58050	external
https://github.com/bikini/exploitarium/tree/main/…	external
https://github.com/libssh2/libssh2/blob/master/sr…	external
https://www.vulncheck.com/advisories/libssh2-inte…	external

JSON

To clipboard

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      "cwe": {
        "id": "CWE-787",
        "name": "Out-of-bounds Write"
      },
      "discovery_date": "2026-06-28T03:01:26.407725+00:00",
      "ids": [
        {
          "system_name": "Red Hat Bugzilla ID",
          "text": "2493955"
        }
      ],
      "notes": [
        {
          "category": "description",
          "text": "A flaw in libssh2 allows a malicious SSH server to trigger a memory overflow by sending a manipulated attribute count. This can cause the connecting client to crash or allow unauthorized code execution.",
          "title": "Vulnerability description"
        },
        {
          "category": "summary",
          "text": "libssh2: libssh2: Heap buffer overflow via integer overflow in publickey attribute allocation",
          "title": "Vulnerability summary"
        },
        {
          "category": "other",
          "text": "This Moderate impact flaw in libssh2 allows a malicious SSH server to trigger a heap buffer overflow in a connecting client. By manipulating the publickey-subsystem response, an attacker could cause an integer overflow, potentially leading to denial of service or arbitrary code execution on Red Hat systems using libssh2 to establish SSH connections.\n\nNote: Red Hat Enterprise Linux (RHEL) 8 and newer are not affected by this flaw, as they do not ship the libssh2 package.",
          "title": "Statement"
        },
        {
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          "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.",
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        }
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        },
        {
          "category": "external",
          "summary": "https://nvd.nist.gov/vuln/detail/CVE-2026-58050",
          "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-58050"
        },
        {
          "category": "external",
          "summary": "https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc",
          "url": "https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc"
        },
        {
          "category": "external",
          "summary": "https://github.com/libssh2/libssh2/blob/master/src/publickey.c",
          "url": "https://github.com/libssh2/libssh2/blob/master/src/publickey.c"
        },
        {
          "category": "external",
          "summary": "https://www.vulncheck.com/advisories/libssh2-integer-overflow-in-publickey-subsystem-attribute-allocation",
          "url": "https://www.vulncheck.com/advisories/libssh2-integer-overflow-in-publickey-subsystem-attribute-allocation"
        }
      ],
      "release_date": "2026-06-28T01:32:53.582000+00:00",
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        {
          "category": "vendor_fix",
          "date": "2026-08-12T02:50:23+00:00",
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            "Red Hat Hardened Images:libssh2-main@aarch64",
            "Red Hat Hardened Images:libssh2-main@noarch",
            "Red Hat Hardened Images:libssh2-main@src",
            "Red Hat Hardened Images:libssh2-main@x86_64"
          ],
          "restart_required": {
            "category": "none"
          },
          "url": "https://access.redhat.com/errata/RHSA-2026:54070"
        },
        {
          "category": "workaround",
          "details": "To mitigate this issue,ensure your applications are running strictly on 64-bit architectures, which naturally prevents the integer overflow from occurring. Additionally, configure your applications to connect only to trusted, verified SSH servers.",
          "product_ids": [
            "Red Hat Hardened Images:libssh2-main@aarch64",
            "Red Hat Hardened Images:libssh2-main@noarch",
            "Red Hat Hardened Images:libssh2-main@src",
            "Red Hat Hardened Images:libssh2-main@x86_64"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.0,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H",
            "version": "3.1"
          },
          "products": [
            "Red Hat Hardened Images:libssh2-main@aarch64",
            "Red Hat Hardened Images:libssh2-main@noarch",
            "Red Hat Hardened Images:libssh2-main@src",
            "Red Hat Hardened Images:libssh2-main@x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Moderate"
        }
      ],
      "title": "libssh2: libssh2: Heap buffer overflow via integer overflow in publickey attribute allocation"
    }
  ]
}

CVE-2026-58050 (GCVE-0-2026-58050)

Vulnerability from cvelistv5 – Published: 2026-06-28 01:32 – Updated: 2026-06-29 12:27

Title

libssh2 - Integer Overflow in publickey Subsystem Attribute Allocation

Summary

libssh2 through 1.11.1 reads an attacker-controlled 32-bit attribute count from a publickey-subsystem response and uses it in the allocation num_attrs * sizeof(libssh2_publickey_attribute) without bounds checking, so on 32-bit platforms the multiplication overflows to an undersized buffer. A malicious SSH server can then drive the attribute-parsing loop to write past the allocation, causing a heap buffer overflow in a connecting libssh2 client.

Severity

7 (High)


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

8.3 (High)


                        
                          CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-29 12:26 UTC

CWE

CWE-190 - Integer Overflow or Wraparound

Assigner

VulnCheck mitre root

References

3 references

URL	Tags
https://github.com/bikini/exploitarium/tree/main/…	exploitthird-party-advisory
https://github.com/libssh2/libssh2/blob/master/sr…	product
https://www.vulncheck.com/advisories/libssh2-inte…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
libssh2	libssh2	Affected: 0 , ≤ 1.11.1 (semver) cpe:2.3:a:libssh2:libssh2::::::::

Date Public

2026-06-25 00:00

Credits

ashdfrkl

Show details on NVD website

JSON

To clipboard

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    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-58050",
    "datePublished": "2026-06-28T01:32:53.582Z",
    "dateReserved": "2026-06-28T00:55:25.426Z",
    "dateUpdated": "2026-06-29T12:27:17.078Z",
    "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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.