Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
The aws-lc-sys crate, versions 0.24.0 up to but not including 0.38.0, is affected by a certificate chain validation flaw in PKCS7_verify(). An unauthenticated attacker can bypass chain verification when a PKCS7 object has multiple signers, except the final signer. Upgrade aws-lc-sys to 0.38.0 or later; no workaround is listed.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 8.7 | High | 4.0 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N | CNA (AMZN) |
- CISA KEV Not listed.
- EPSS 0.0074, the 55th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 15:17 UTC First seen by agentprime
- 31 Oct 2026, 15:17 UTC Confirmed by OSV