Description
libcrux-ecdh and libcrux-ed25519 before 0.0.6, and libcrux-psq before 0.0.7, contain cryptographic implementation bugs. libcrux-ecdh did not properly check length and clamping during X25519 secret validation (and had a broken clamping check for imported X25519 secret keys); libcrux-ed25519 performed a duplicated clamping step during key generation; and libcrux-psq panicked instead of propagating an AEADError. These were fixed in the respective patched releases.
Published: 2026-08-19
Score: 8.7 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The vulnerability exists in the libcrux cryptographic library prior to certain patch releases. libcrux-ecdh fails to check the proper length and clamping of X25519 secrets, and its import validation is broken, which could allow an attacker to use an invalid key that bypasses security checks. libcrux-ed25519 performs a duplicate clamping operation during key generation, potentially creating weaker keys. libcrux-psq panics rather than reporting an AEADError, which could cause denial of service or unexpected termination of the calling application.

Affected Systems

Affected products are the open-source library celabshq/libcrux and several of its sub-packages: libcrux-ecdh, libcrux-ed25519, and libcrux-psq. The vulnerability is present in all releases older than libcrux-ecdh 0.0.6, libcrux-ed25519 0.0.6, and libcrux-psq 0.0.7. No specific operating system or application is listed, so any environment that incorporates these library versions is potentially exposed.

Risk and Exploitability

The CVSS score of 8.7 classifies the issue as high severity, reflecting the significant impact on confidentiality and integrity if the vulnerability is exploited. The EPSS score is not available, and the vulnerability is not currently listed in CISA's KEV catalog. Because the flaw resides within cryptographic key handling, exploitation would likely require the ability to supply crafted keys or inputs to the affected library functions—an attack that could be possible from a remote client in a server application or from a local user on a system that loads the library. Given the high severity and the lack of a public exploit listing, administrators should treat this as a priority patching issue.

Generated by OpenCVE AI on August 19, 2026 at 18:58 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Update all libcrux components to the patched versions (libcrux-ecdh ≥0.0.6, libcrux-ed25519 ≥0.0.6, libcrux-psq ≥0.0.7).
  • Remove or disable any custom key validation that bypasses library checks.
  • Test cryptographic functions to verify that input keys are properly clamped and that the panic is no longer triggered for erroneous inputs.

Generated by OpenCVE AI on August 19, 2026 at 18:58 UTC.

Tracking

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Advisories

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History

Wed, 19 Aug 2026 14:15:00 +0000

Type Values Removed Values Added
Description libcrux-ecdh and libcrux-ed25519 before 0.0.6, and libcrux-psq before 0.0.7, contain cryptographic implementation bugs. libcrux-ecdh did not properly check length and clamping during X25519 secret validation (and had a broken clamping check for imported X25519 secret keys); libcrux-ed25519 performed a duplicated clamping step during key generation; and libcrux-psq panicked instead of propagating an AEADError. These were fixed in the respective patched releases.
Title libcrux before 0.0.6 Cryptographic Implementation Bug Fixes
Weaknesses CWE-347
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-19T14:02:14.481Z

Reserved: 2026-08-19T11:36:02.574Z

Link: CVE-2026-76234

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-19T14:17:52.797

Modified: 2026-08-19T14:17:52.797

Link: CVE-2026-76234

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-19T19:00:05Z

Weaknesses
  • CWE-347

    Improper Verification of Cryptographic Signature