Skip to main content
VulnerabilityPublished

CVE-2026-119284: joserfc · Compact JWS size guard allocates attacker-controlled segments before rejection

Affects mcpmSource GCVE Database

0
Compare
Authoritative record:CVE-2026-119284· Medium 6.9

Not known to be exploited · CVSS 6.9 Medium : upgrade to 2.15.0_5 when convenient.

Data as of 31 Oct 2026, 16:07 UTC

CVSS 4.0 base score
6.9Medium
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS scores by source
CNA (GitHub_M)CVSS 4.06.9
Patch
Available – fixed in 2.15.0_5
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 29 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: 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 30 Oct 2026.

What to do

Upgrade mcpm to 2.15.0_5.

Affected software

ProductAffectedFixed in
Homebrewmcpmpkg:brew/mcpmOther threatsAffected
  • >=2.14.0_4 <2.15.0_5
Fixed in
  • 2.15.0_5

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 joserfc version 2.15.0_5 that fixes this issue by validating the input size before splitting and allocating memory. Users should upgrade to version 2.15.0_5 or later to remediate this vulnerability. No additional mitigation is required beyond applying the official fix.

Description

joserfc version range >=2.14.0_4 <2.15.0_5 has a vulnerability where the compact JWS size guard allocates attacker-controlled segments before rejecting them, causing unnecessary memory allocation. This occurs because the library calls bytes.split() on the input before validating its size, leading to a copy of the payload being made even if it will be rejected. The issue is fixed in version 2.15.0_5.

References

Community reviews

Loading reviews…