CVE-2026-93602: rustls webpki
Vulnerability summary
CVE-2026-93602 is a medium (CVSS 5.9) vulnerability in rustls webpki. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.3% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 6 · Related 6Timeline
- 18-09-2026PublishedVulnerability first disclosed.
- 18-09-2026Last modifiedVulnerability information updated.
Description
rustls-webpki versions before 0.103.10 and 0.104.0-alpha.5 contain faulty CRL authority-matching logic that compares only the first distributionPoint against each CRL's IssuingDistributionPoint, ignoring additional distributionPoints. Attackers with a compromised trusted issuing authority can present revoked certificates that pass revocation checks under UnknownStatusPolicy::Allow, or cause incorrect errors under the default deny policy.
CVSS metrics
8 scores · 5 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated5.9MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- OSV · DebianEcosystem advisory · calculated5.9MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/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
- NVDNIST5.9MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/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
- OSV · UbuntuEcosystem advisory · calculated4.4MediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N
- OSV · Crates.ioEcosystem advisory · calculated4.4MediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N
- NVDNIST4.4MediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N
EPSS trend
Probability
0.20%
Chance of exploitation in the next 30 days
Percentile
9%
Versus all other CVEs
30-day change
0.00 pp
From 0.20% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Crates.Io1 product
- rustls-webpki≥ 0.104.0-alpha.1, < 0.104.0-alpha.5 | ≥ 0.102.0-alpha.0, < 0.103.10
Debian1 product
- rust-rustls-webpkiAll versions (No fix recorded) | < 0.103.10+ds-1
Rustls1 product
- webpki≥ 0.102.0-alpha.0, < 0.103.10 | ≥ 0.104.0-alpha.1, < 0.104.0-alpha.5
Ubuntu1 product
- rust-rustls-webpkiAll versions (No fix recorded)
4 vendors · 4 products
References
8 links- www.vulncheck.com/advisories/rustls-webpki-before-0.103.10-crl-revocation-check-bypassThird Party AdvisoryREPORT
- github.com/rustls/webpkiPACKAGE