OpenSSL is widely used; use-after-free may enable remote code execution via PKCS7 APIs, impacting core crypto library across industries.
CVE-2026-45447
OpenSSL PKCS7 verification use-after-free may enable RCE.
Is CVE-2026-45447 being exploited?
Not confirmed. CVE-2026-45447 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 3.6% probability of exploitation in the next 30 days.
How severe is CVE-2026-45447?
CVE-2026-45447 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-45447?
Yes. A fix has been recorded for CVE-2026-45447. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-45447 affect?
CVE-2026-45447 affects OpenSSL PKCS7 APIs. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-45447?
Upgrade OpenSSL to patched version.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution via crafted PKCS#7/S/MIME message; memory corruption from use-after-free during PKCS7_verify.
Immediate action required
- affected>= 4.0.0 and < 4.0.1
- affected>= 3.6.0 and < 3.6.3
- affected>= 3.5.0 and < 3.5.7
- affected>= 3.4.0 and < 3.4.6
- affected>= 3.0.0 and < 3.0.21
- affected>= 1.1.1 and < 1.1.1zh
- affected>= 1.0.2 and < 1.0.2zq
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.