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VulnerabilityPublished Updated

CVE-2026-102274: PyJWT · Malformed RSA JWK aborts parsing of an entire JWK Set

Affects hermes-agentSource GCVE Database

0
Authoritative record:CVE-2026-102274· Medium 5.9

Not known to be exploited · CVSS 5.9 Medium : upgrade to 0.22.4 when convenient.

Data as of 27 Oct 2026, 21:00 UTC

CVSS 3.1 base score
5.9Medium
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 0.22.4
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 28 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 26 Oct 2026.

What to do

Upgrade hermes-agent to 0.22.4.

Affected software

ProductAffectedFixed in
Homebrewhermes-agentpkg:brew/hermes-agentOther threatsAffected
  • >=0.21.6 <0.22.4
  • >=2026.4.30 <=2026.9.24
Fixed in
  • 0.22.4

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available in PyJWT version 0.22.4 that addresses this issue by converting the ValueError to a PyJWTError subclass, allowing the existing error handling to skip malformed keys. Users should upgrade to version 0.22.4 or later. Until patched, applications should be aware that malformed RSA keys in JWK Sets can cause unhandled exceptions and consider validating keys individually before adding them to trusted sets.

Description

A vulnerability in PyJWT causes a malformed RSA JWK inside a JWK Set to abort parsing of the entire set instead of skipping the malformed key. This occurs because a built-in Python ValueError raised during RSA key parsing is not caught by PyJWT's error handling, causing the constructor to fail and no keys to be added from the set.

References

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