GHSA-9f94-5g5w-gf6r CVE-2026-4428 RUSTSEC-2026-0042 RUSTSEC-2026-0048
CRL Distribution Point Scope Check Logic Error in AWS-LC
- Severity
- 9.1 / 10
- Critical · CVSS 4.0
- Exploit chance (EPSS)
- 0.26%
- Chance of exploitation in the next 30 days. Higher than 17.36% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-295 Improper Certificate Validation
- Fix
- Available
- 2 packages have a fixed version
Description
Summary
AWS-LC is an open-source, general-purpose cryptographic library.
Impact
A logic error in CRL distribution point matching in AWS-LC allows a revoked certificate to bypass revocation checks during certificate validation, when the application enables CRL checking and uses partitioned CRLs with Issuing Distribution Point (IDP) extensions.
Customers of AWS services do not need to take action. aws-lc-sys and aws-lc-fips-sys contain code from AWS-LC. Applications using aws-lc-sys or aws-lc-fips-sys should upgrade to the most recent releases of aws-lc-sys or aws-lc-fips-sys.
Impacted versions:
- aws-lc-sys >= v0.15.0, < v0.39.0
- aws-lc-fips-sys >= v0.13.0, < v0.13.13
Patches
The patch is included in aws-lc-sys v0.39.0 and aws-lc-fips-sys v0.13.13.
Workarounds
Applications can workaround this issue if they do not enable CRL checking (X509_V_FLAG_CRL_CHECK). Applications using complete (non-partitioned) CRLs without IDP extensions are also not affected.
Otherwise, there is no workaround and applications using aws-lc-sys or aws-lc-fips-sys should upgrade to the most recent releases of aws-lc-sys or aws-lc-fips-sys.
References
If you have any questions or comments about this advisory, we ask that you contact AWS Security via our vulnerability reporting page or directly via email to aws-security@amazon.com. Please do not create a public GitHub issue.
Affected versions
crates.io
| Package | Vulnerable | Fixed in |
|---|---|---|
| aws-lc-fips-sys | >= 0.13.0, < 0.13.13 |
0.13.13 |
| aws-lc-sys | >= 0.15.0, < 0.39.0 |
0.39.0 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
aws-lc-fips-sys crates.io → 0.13.13
- cargo
cargo update -p aws-lc-fips-sys --precise 0.13.13
aws-lc-sys crates.io → 0.39.0
- cargo
cargo update -p aws-lc-sys --precise 0.39.0
Severity breakdown
CVSS 4.0 9.1
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Attack vector
- Network
- Attack complexity
- High
- Attack requirements
- Present
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- High
- Integrity (vulnerable system)
- High
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
- Exploit maturity
- Not defined
- Scope
- X
CVSS 3.1 7.4
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Weakness
CWE-295: Improper Certificate Validation
The product does not validate, or incorrectly validates, a certificate.
How to prevent it
- Architecture and Design, Implementation: Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
- Implementation: If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
References
Packages
Other links
- github.com/aws/aws-lc-rs/security/advisories/GHSA-9f94-5g5w-gf6r
- aws.amazon.com/security/security-bulletins/2026-010-AWS
- rustsec.org/advisories/RUSTSEC-2026-0042.html
- rustsec.org/advisories/RUSTSEC-2026-0048.html
- aws.amazon.com/security/security-bulletins/2026-010-AWS
- github.com/aws/aws-lc/releases/tag/v1.71.0
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-394x-vwmw-crm3 AWS-LC X.509 Name Constraints Bypass via Wildcard/Unicode CN | High | Also affects aws-lc-sys |
| GHSA-vw5v-4f2q-w9xf AWS-LC has PKCS7_verify Certificate Chain Validation Bypass | High | Also affects aws-lc-sys |
| GHSA-hfpc-8r3f-gw53 AWS-LC has PKCS7_verify Signature Validation Bypass | High | Also affects aws-lc-sys |
| GHSA-65p9-r9h6-22vj AWS-LC has Timing Side-Channel in AES-CCM Tag Verification | Medium | Also affects aws-lc-fips-sys |
| GHSA-4487-j8r4-4g2f Forge: verifyCertificateChain() removes trusted CA certificates with the same subject from the CA store | Low | Same weakness, CWE-295 |
| GHSA-5x38-2vff-x55p Forge: X.509 basicConstraints bypass in verifyCertificateChain() via deprecated extension OIDs 2.5.29.10 and 2.5.29.13 | High | Same weakness, CWE-295 |
| EEF-CVE-2026-115693 Custom cacerts or cacertfile do not restrict trust to the pinned CA in hackney | Not rated yet | Same weakness, CWE-295 |
| GHSA-6q48-6c7w-9gw2 certifi bundles emSign root CAs with compromised intermediate CA keys | Critical | Same weakness, CWE-295 |
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