CVE-2026-45447
HIGH 8.8Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during PKCS#7 signature verification. Impact summary: A use-after-free may result in process crashes, heap corruption, or potentially remote code execution. When processing a PKCS#7 or S/MIME signed message, if the SignedData digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may incorrectly free a caller-owned BIO during PKCS7_verify(). A subsequent use of the BIO by the calling application results in a use-after-free condition. In the common case this occurs when the application later calls BIO_free() on the BIO originally passed to PKCS7_verify(). Depending on allocator behavior and application-specific BIO usage patterns, this may result in a crash or other memory corruption. In some application contexts this may potentially be exploitable for remote code execution. Applications that process PKCS#7 or S/MIME signed messages using OpenSSL PKCS#7 APIs may be affected. Applications using the CMS APIs for this processing are not affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.
Severe if exploited (CVSS 8.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
2.7%chance of exploitation in 30 days · 84th percentile
Impact if exploited
8.8CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Affected
Products Openssl Red Hat Enterprise Linux Appstream (V. 10) Red Hat Enterprise Linux Appstream (V. 9) Red Hat Enterprise Linux Baseos (V. 10) Red Hat Enterprise Linux Baseos (V. 8) Red Hat Enterprise Linux Baseos Eus Extension (V.8.6) Red Hat Enterprise Linux Baseos E4s (V.8.8) Red Hat Enterprise Linux Baseos Tus (V.8.8)
Weakness (CWE)
- CWE-416: Use after free
- CWE-825
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
Patches & mitigations
- https://github.com/openssl/openssl/commit/3aad5eb7af4de4ee0633c30a8541a54d9bbde63c
- https://github.com/openssl/openssl/commit/c505d7559da5d5f9f2c3913c6883a5562ce7273e
- https://github.com/openssl/openssl/commit/7d4a980c62258c5910cc883936e0c8dbab4d75a8
- https://github.com/openssl/openssl/commit/a541ae8bfe849a30cc885e8780715c0f488e496c
- https://github.com/openssl/openssl/commit/9dfd688ad2290fc5075cacbc9bf0c9a93eefed54