GHSA-hvh4-5qr6-3v7r
Observable Timing Discrepancy in pypqc
GHSA-hvh4-5qr6-3v7r is a high vulnerability (CVSS 7.8) in pypqc, published June 5, 2024. No source lists public exploit code. No source names a fixed version.
- Severity
- 7.8 HighCVSS 3.1, GitHub Advisories
- Exploit chance
- UnscoredNo EPSS score yet
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
- No fix listedNo source names one
Description
Impact
kyber512, kyber768, and kyber1024 on Mac OS (or when compiled with clang) only: An attacker able to submit many decapsulation requests against a single private key, and to gain timing information about the decapsulation, could recover the private key. Proof-of-concept exploit exists for a local attacker.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N/E:P/RL:U/RC:C
Patches
No patch is currently available / pending upstream PQClean#556.
Workarounds
No workarounds have been reported. The 0.0.7 -> 0.0.7.1 upgrade, when available, should be a drop-in replacement<!--; it has no known breaking changes-->.
References
https://github.com/antoonpurnal/clangover
https://www.github.com/PQClean/PQClean/issues/556
https://www.github.com/pq-crystals/kyber/commit/9b8d30698a3e7449aeb34e62339d4176f11e3c6c
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
- High
- Integrity
- Low
- Availability
- None
Affected packages
What each source reports
GitHub Advisories Score used
Observable Timing Discrepancy in pypqc
Impact
kyber512, kyber768, and kyber1024 on Mac OS (or when compiled with clang) only: An attacker able to submit many decapsulation requests against a single private key, and to gain timing information about the decapsulation, could recover the private key. Proof-of-concept exploit exists for a local attacker.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N/E:P/RL:U/RC:C
Patches
No patch is currently available / pending upstream PQClean#556.
Workarounds
No workarounds have been reported. The 0.0.7 -> 0.0.7.1 upgrade, when available, should be a drop-in replacement<!--; it has no known breaking changes-->.
References
https://github.com/antoonpurnal/clangover
https://www.github.com/PQClean/PQClean/issues/556
https://www.github.com/pq-crystals/kyber/commit/9b8d30698a3e7449aeb34e62339d4176f11e3c6c
- Record
GHSA-hvh4-5qr6-3v7r- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N/E:P/RL:U/RC:C - Weakness
- CWE-385, CWE-733
- Updated
- 2026-11-02
OSV
Observable Timing Discrepancy in pypqc
Impact
kyber512, kyber768, and kyber1024 on Mac OS (or when compiled with clang) only: An attacker able to submit many decapsulation requests against a single private key, and to gain timing information about the decapsulation, could recover the private key. Proof-of-concept exploit exists for a local attacker.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N/E:P/RL:U/RC:C
Patches
No patch is currently available / pending upstream PQClean#556.
Workarounds
No workarounds have been reported. The 0.0.7 -> 0.0.7.1 upgrade, when available, should be a drop-in replacement<!--; it has no known breaking changes-->.
References
https://github.com/antoonpurnal/clangover
https://www.github.com/PQClean/PQClean/issues/556
https://www.github.com/pq-crystals/kyber/commit/9b8d30698a3e7449aeb34e62339d4176f11e3c6c
- Record
GHSA-hvh4-5qr6-3v7r- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N/E:P/RL:U/RC:C - Weakness
- CWE-385, CWE-733
- 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.