CVE-2026-89086: OCaml jose · Improper Verification of Cryptographic Signature
Affects OCaml joseSource CVE Database V5
Not known to be exploited · CVSS 9.1 Critical : upgrade to 0.11.0 as a priority.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 19% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.11.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Upgrade jose and github.com/ulrikstrid/ocaml-jose to 0.11.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| OCamljose | Affected
| Fixed in
|
Gogithub.com/ulrikstrid/ocaml-josepkg:golang/github.com/ulrikstrid/ocaml-joseOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, users should avoid using vulnerable versions of the jose package or implement additional signature verification controls externally.
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.