CVE-2026-4428: Aws lc sys · CRL Distribution Point Scope Check Logic Error in AWS-LC
Affects aws-lc-sysSource GCVE Database
Not known to be exploited · CVSS 7.4 High : upgrade to 0.39.0 soon.
Data as of 9 Nov 2026, 11:23 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 17% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.39.0
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 19 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 8 Nov 2026.
What to do
Upgrade aws-lc-sys to 0.39.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
crates.ioaws-lc-syspkg:cargo/aws-lc-sysOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in aws-lc-sys version 0.39.0. Applications using affected versions should upgrade to 0.39.0 or later. Customers of AWS services do not need to take any action as AWS manages remediation for their cloud services. Workarounds include disabling CRL checking (not enabling X509_V_FLAG_CRL_CHECK) or using complete (non-partitioned) CRLs without IDP extensions. No other workaround is available.
Description
CVE-2026-4428 is a logic error in the CRL distribution point matching of AWS-LC that allows revoked certificates to bypass revocation checks during validation when CRL checking is enabled and partitioned CRLs with Issuing Distribution Point extensions are used. Applications using aws-lc-sys versions from 0.15.0 up to but not including 0.39.0 are affected. AWS customers using AWS services do not need to take action. The issue is fixed in aws-lc-sys version 0.39.0.