Vulnerability-Lookup

ALSA-2026:80605

Vulnerability from osv_almalinux – Published: 2026-10-12 00:00 – Updated: 2026-10-12 13:44 – Source website

Summary

Critical: cjose security update

Details

CJose is C library implementing the Javascript Object Signing and Encryption (JOSE).

Security Fix(es):

cjose: OpenIDC/cjose uses all-zero Content Encryption Key for AES-CBC-HMAC JWE encryption (CVE-2026-53939)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

References

URL

Type

	https://access.redhat.com/errata/RHSA-2026:80605	ADVISORY
	https://access.redhat.com/security/cve/CVE-2026-53939	REPORT
	https://bugzilla.redhat.com/2530243	REPORT
	https://errata.almalinux.org/10/ALSA-2026-80605.html	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "AlmaLinux:10",
        "name": "cjose"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.6.2.2-7.el10_2.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:10",
        "name": "cjose-devel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.6.2.2-7.el10_2.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "CJose is C library implementing the Javascript Object Signing and Encryption (JOSE).  \n\nSecurity Fix(es):  \n\n  * cjose: OpenIDC/cjose uses all-zero Content Encryption Key for AES-CBC-HMAC JWE encryption (CVE-2026-53939)\n\n\nFor more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.\n",
  "id": "ALSA-2026:80605",
  "modified": "2026-10-12T13:44:25Z",
  "published": "2026-10-12T00:00:00Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/errata/RHSA-2026:80605"
    },
    {
      "type": "REPORT",
      "url": "https://access.redhat.com/security/cve/CVE-2026-53939"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/2530243"
    },
    {
      "type": "ADVISORY",
      "url": "https://errata.almalinux.org/10/ALSA-2026-80605.html"
    }
  ],
  "related": [
    "CVE-2026-53939"
  ],
  "summary": "Critical: cjose security update"
}

CVE-2026-53939 (GCVE-0-2026-53939)

Vulnerability from cvelistv5 – Published: 2026-09-08 23:36 – Updated: 2026-09-09 15:12

Title

OpenIDC/cjose uses all-zero Content Encryption Key for AES-CBC-HMAC JWE encryption

Summary

OpenIDC/cjose is a C library implementing the Javascript Object Signing and Encryption (JOSE). In versions 0.6.1 through 0.6.2.5, when cjose encrypts a JWE using an AES-CBC-HMAC content-encryption algorithm (`A128CBC-HS256`, `A192CBC-HS384`, or `A256CBC-HS512`) together with any key-management algorithm that generates a fresh content-encryption key (CEK), the CEK is all zero bytes instead of being randomly generated. The resulting JWE is therefore encrypted and authenticated under a fixed, publicly known key, so anyone who obtains the JWE can recover the plaintext and forge or modify the content. This is fixed in version 0.6.2.6 by `_cjose_jwe_set_cek_aes_cbc()` generating the CEK from `RAND_bytes`. A regression test asserts that the `encrypted_key` differs across two encryptions for each AES-CBC-HMAC variant. Until upgrading, for data encrypted with cjose, three options are available. Use an AES-GCM `enc` (`A128GCM` / `A192GCM` / `A256GCM`) instead of an AES-CBC-HMAC `enc`, use `alg=dir` with a caller-supplied CEK, or avoid using cjose for JWE encryption with the affected algorithm pair. These are mitigations for new ciphertexts only; data already encrypted under the zero key remains compromised and should be re-encrypted (and any secrets it contained rotated).

Severity

9.1 (Critical)


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

SSVC

Exploitation: poc Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-09 15:12 UTC

CWE

CWE-321 - Use of Hard-coded Cryptographic Key
CWE-330 - Use of Insufficiently Random Values

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7566 records in the last 180 days details

References

3 references

URL	Tags
https://github.com/OpenIDC/cjose/security/advisor…	x_refsource_CONFIRM
https://github.com/OpenIDC/cjose/commit/2a6e5bd96…	x_refsource_MISC
https://github.com/OpenIDC/cjose/releases/tag/v0.6.2.6	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
OpenIDC	cjose	Affected: >= 0.6.1, < 0.6.2.6

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-53939",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-09T15:12:10.094529Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-09T15:12:15.459Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/OpenIDC/cjose/security/advisories/GHSA-f6wf-pqg3-6wqq"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "cjose",
          "vendor": "OpenIDC",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.6.1, \u003c 0.6.2.6"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "OpenIDC/cjose is a C library implementing the Javascript Object Signing and Encryption (JOSE). In versions 0.6.1 through 0.6.2.5, when cjose encrypts a JWE using an AES-CBC-HMAC content-encryption algorithm (`A128CBC-HS256`, `A192CBC-HS384`, or `A256CBC-HS512`) together with any key-management algorithm that generates a fresh content-encryption key (CEK), the CEK is all zero bytes instead of being randomly generated. The resulting JWE is therefore encrypted and authenticated under a fixed, publicly known key, so anyone who obtains the JWE can recover the plaintext and forge or modify the content. This is fixed in version 0.6.2.6 by `_cjose_jwe_set_cek_aes_cbc()` generating the CEK from `RAND_bytes`. A regression test asserts that the `encrypted_key` differs across two encryptions for each AES-CBC-HMAC variant. Until upgrading, for data encrypted with cjose, three options are available. Use an AES-GCM `enc` (`A128GCM` / `A192GCM` / `A256GCM`) instead of an AES-CBC-HMAC `enc`,  use `alg=dir` with a caller-supplied CEK, or avoid using cjose for JWE encryption with the affected algorithm pair. These are mitigations for new ciphertexts only; data already encrypted under the zero key remains compromised and should be re-encrypted (and any secrets it contained rotated)."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-321",
              "description": "CWE-321: Use of Hard-coded Cryptographic Key",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-330",
              "description": "CWE-330: Use of Insufficiently Random Values",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-08T23:36:13.668Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/OpenIDC/cjose/security/advisories/GHSA-f6wf-pqg3-6wqq",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/OpenIDC/cjose/security/advisories/GHSA-f6wf-pqg3-6wqq"
        },
        {
          "name": "https://github.com/OpenIDC/cjose/commit/2a6e5bd969fa20059fb00913fb9f57d77ea6a4d9",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/OpenIDC/cjose/commit/2a6e5bd969fa20059fb00913fb9f57d77ea6a4d9"
        },
        {
          "name": "https://github.com/OpenIDC/cjose/releases/tag/v0.6.2.6",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/OpenIDC/cjose/releases/tag/v0.6.2.6"
        }
      ],
      "source": {
        "advisory": "GHSA-f6wf-pqg3-6wqq",
        "discovery": "UNKNOWN"
      },
      "title": "OpenIDC/cjose uses all-zero Content Encryption Key for AES-CBC-HMAC JWE encryption"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-53939",
    "datePublished": "2026-09-08T23:36:13.668Z",
    "dateReserved": "2026-06-11T15:46:12.318Z",
    "dateUpdated": "2026-09-09T15:12:15.459Z",
    "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.

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