GHSA-fh2r-99q2-6mmg
rustls-webpki: CPU denial of service in certificate path building
GHSA-fh2r-99q2-6mmg is a high vulnerability (CVSS 7.5) in rustls-webpki, published August 22, 2023. No source lists public exploit code. Fixed in rustls-webpki 0.100.2.
- Severity
- 7.5 HighCVSS 3.0, GitHub Advisories
- Exploit chance
- UnscoredNo EPSS score yet
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
0.100.2rustls-webpki +2 more
Description
When this crate is given a pathological certificate chain to validate, it will spend CPU time exponential with the number of candidate certificates at each step of path building.
Both TLS clients and TLS servers that accept client certificate are affected.
We now give each path building operation a budget of 100 signature verifications.
The original webpki crate is also affected, see GHSA-8qv2-5vq6-g2g7.
This was previously reported in the original crate https://github.com/briansmith/webpki/issues/69 and re-reported to us recently.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Affected packages
| Package | Affected | Fixed |
|---|---|---|
rustls-webpkicrates.io | before 0.100.2 | 0.100.2 |
rustls-webpkicrates.io | 0.101.0 up to 0.101.4 | 0.101.4 |
rustls-webpkicrates.io | 0.0.0-0 up to 0.100.2, 0.101.0 up to 0.101.4 | 0.100.20.101.4 |
What each source reports
GitHub Advisories Score used
rustls-webpki: CPU denial of service in certificate path building
When this crate is given a pathological certificate chain to validate, it will spend CPU time exponential with the number of candidate certificates at each step of path building.
Both TLS clients and TLS servers that accept client certificate are affected.
We now give each path building operation a budget of 100 signature verifications.
The original webpki crate is also affected, see GHSA-8qv2-5vq6-g2g7.
This was previously reported in the original crate https://github.com/briansmith/webpki/issues/69 and re-reported to us recently.
- Record
GHSA-fh2r-99q2-6mmg- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
OSV
rustls-webpki: CPU denial of service in certificate path building
When this crate is given a pathological certificate chain to validate, it will spend CPU time exponential with the number of candidate certificates at each step of path building.
Both TLS clients and TLS servers that accept client certificate are affected.
We now give each path building operation a budget of 100 signature verifications.
The original webpki crate is also affected, see GHSA-8qv2-5vq6-g2g7.
This was previously reported in the original crate https://github.com/briansmith/webpki/issues/69 and re-reported to us recently.
- Record
GHSA-fh2r-99q2-6mmg- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
OSVRUSTSEC-2023-0053
rustls-webpki: CPU denial of service in certificate path building
When this crate is given a pathological certificate chain to validate, it will spend CPU time exponential with the number of candidate certificates at each step of path building.
Both TLS clients and TLS servers that accept client certificate are affected.
We now give each path building operation a budget of 100 signature verifications.
The original webpki crate is also affected.
This was previously reported in the original crate https://github.com/briansmith/webpki/issues/69 and re-reported to us recently by Luke Malinowski.
- Record
RUSTSEC-2023-0053- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | GitHub Advisories, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
References
github.com/rustls/webpki/commit/4ea052366f342a06344aab589565179b59b342d3
rustsec.org/advisories/RUSTSEC-2023-0053.html
crates.io/crates/rustls-webpki