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Fencer Intel
medium 6.5

CVE-2026-126405 json

Coder from 2.38.0 before 2.38.4 Memory Exhaustion DoS via Web Push

published 17d ago modified 2d ago also EUVD-2026-125160 , GHSA-64xh-rgcx-gg65

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository coder/coder. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits
0
none known

Summary

Coder 2.21.0 before 2.29.24, 2.30.0 before 2.34.16, 2.35.0 before 2.36.11, 2.37.0 before 2.37.8, and 2.38.0 before 2.38.4 reads Web Push endpoint responses in webpushSend with io.ReadAll, without a size limit or client timeout. Any authenticated user can register a subscription via POST /api/v2/users/{user}/webpush/subscription pointing to a server returning an endless body, exhausting coderd memory and crashing the API, dashboard, and workspace connections.

Patch / fix

  • coder coder 2.29.24, 2.34.16, 2.36.0, 2.36.11, 2.37.8, 2.38.4

Is CVE-2026-126405 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-14).

CVSS scores

assigned by version score vector
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • coder coder

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of coder/coder published their own advisory on GitHub. Reviewed sources take precedence over it.