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Vulnerability record · CVE-2026-89086 · published 10 September 2026

CVE-2026-89086: Improper verification of cryptographic signature vulnerability

In the jose package before 0.11.0 for OCaml, library calls to validate an RSA signature only confirm that PKCS #1 decoding succeeds, and proceed to declare the signature valid without the required steps that involve the public key.

9.1 CVSS 3.1 Critical EPSS 0.28% · top 82.0% CWE-347 · Improper verification of cryptographic signature Deferred
9.1CVSS 3.1 base score
0.28%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
2References
22 Sep 2026Last modified by NVD

Description

In the jose package before 0.11.0 for OCaml, library calls to validate an RSA signature only confirm that PKCS #1 decoding succeeds, and proceed to declare the signature valid without the required steps that involve the public key.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References

LinkTags
https://github.com/ulrikstrid/ocaml-jose/commit/cf17d991ec6a0d1997956b6c7799890f9c28879e
https://osv.dev/vulnerability/OSEC-2026-19

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Source: NIST National Vulnerability Database (record CVE-2026-89086), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.