Use After Free in Openssl
CVE-2026-45447
Issue 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…
Vulnerability class: Use-After-Free
EPSS: 0.052 (91.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Openssl — versions 4.0.0, 3.6.0, 3.5.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- openssl-security@openssl.org
- openssl-security@openssl.org
- openssl-security@openssl.org
- openssl-security@openssl.org
- openssl-security@openssl.org
- openssl-security@openssl.org (vendor-advisory, Vendor Advisory)
- openssl-security@openssl.org (Patch, patch)
- openssl-security@openssl.org (Patch, patch)
- openssl-security@openssl.org (Patch, patch)
- openssl-security@openssl.org (Patch, patch)
Frequently asked questions
- What is CVE-2026-45447?
- CVE-2026-45447 is a high-severity vulnerability in Openssl, classified under Use After Free. CVSS score: 8.8/10. Published 2026-06-09.
- How severe is CVE-2026-45447?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2026-45447 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.