PKCS#12 Files with PBMAC1 Are Accepted with Short HMAC Keys (OpenSSL OpenSSL)

CVE-2026-34181
HIGH 7.4

At a glance

Source
NVD
EPSS
EPSS 0.38 % · percentile 32 ()
State
PUBLISHED
Published
Updated
Assigner
openssl
NVD status
Analyzed

Description

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.

Weaknesses (CWE)

  • CWE-354 — Improper Validation of Integrity Check Value

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NCISA-ADP
CVSS 3.1HIGH 7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NNVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
OpenSSL · OpenSSLaffected 4.0.0 < 4.0.1 ; affected 3.6.0 < 3.6.3 ; affected 3.5.0 < 3.5.7 ; affected 3.4.0 < 3.4.6

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD