GHSA-4JGC-CJ59-F9MM

Vulnerability from github – Published: 2026-06-09 18:30 – Updated: 2026-06-10 18:31
VLAI
Details

Issue Summary: The PKCS#12 file processing fails to perform sufficient input validation for files that use Password-Based Message Authentication Code 1 (PBMAC1) integrity mechanism allowing a certificate and private key forgery.

Impact Summary: An attacker impersonating a user can cause a service reading PKCS#12 files to accept forged certificates and private keys with a 1 in 256 probability.

If a service accepting PKCS#12 files is using passwords for authenticating the received files, the attacker can create unencrypted PKCS#12 files that use PBMAC1 authentication that specifies an HMAC key of only one byte, allowing them to craft a file that will be accepted with a 1 in 256 probability. That would then cause the service to accept a certificate and private key controlled by the attacker.

The FIPS modules are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

Severity
7.4 (High)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2026-34181"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-354"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-09T17:17:04Z",
    "severity": "HIGH"
  },
  "details": "Issue Summary: The PKCS#12 file processing fails to perform sufficient input\nvalidation for files that use Password-Based Message Authentication Code 1\n(PBMAC1) integrity mechanism allowing a certificate and private key forgery.\n\nImpact Summary: An attacker impersonating a user can cause a service reading\nPKCS#12 files to accept forged certificates and private keys with a 1 in 256\nprobability.\n\nIf a service accepting PKCS#12 files is using passwords for authenticating\nthe received files, the attacker can create unencrypted PKCS#12 files that\nuse PBMAC1 authentication that specifies an HMAC key of only one byte, allowing\nthem to craft a file that will be accepted with a 1 in 256 probability.\nThat would then cause the service to accept a certificate and private key\ncontrolled by the attacker.\n\nThe FIPS modules are not affected by this issue, as the affected code is\noutside the OpenSSL FIPS module boundary.",
  "id": "GHSA-4jgc-cj59-f9mm",
  "modified": "2026-06-10T18:31:40Z",
  "published": "2026-06-09T18:30:42Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34181"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/0300eb9ddce7a0895bf301a4b0c03a9da2313a0f"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/79eb76a937e474bb7610a0a3dc57131dc8dc6610"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/85dcbb3abaa4878af5c8fbbe11bce708fcf984a7"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/ec36f2417c4ddd8cabce4b4a60a3d7a7365f2d81"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/security/commit/0300eb9ddce7a0895bf301a4b0c03a9da2313a0f"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/security/commit/79eb76a937e474bb7610a0a3dc57131dc8dc6610"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/security/commit/85dcbb3abaa4878af5c8fbbe11bce708fcf984a7"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/security/commit/ec36f2417c4ddd8cabce4b4a60a3d7a7365f2d81"
    },
    {
      "type": "WEB",
      "url": "https://openssl-library.org/news/secadv/20260609.txt"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.