CVE-2026-3336
Unauthenticated bypass of PKCS7 chain validation in AWS-LC; upgrade to 1.69.0.
Is CVE-2026-3336 being exploited?
Not confirmed. CVE-2026-3336 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 0.77% probability of exploitation in the next 30 days.
How severe is CVE-2026-3336?
CVE-2026-3336 is rated High with a CVSS score of 8.7. 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-2026-3336?
Yes. A fix has been recorded for CVE-2026-3336. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-3336 affect?
CVE-2026-3336 affects Applications using AWS-LC. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-3336?
Upgrade AWS-LC to v1.69.0
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Bypasses PKCS7 cert-chain verification for multi-signer data, enabling impersonation in apps using AWS-LC.
Patch when possible
- affected>= 1.41.0 and < 1.69.0
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.