Colord: Slow rejection of oversized malformed color strings

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.9 · 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 · score source

EPSS

• CVE-2026-85062: 0.51% estimated exploitation activity in the next 30 days; percentile 43.30 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact colord's CSS color string matchers described a number as ([+-]?\d\.?\d+). In that form \d and \d+ can match the same digits, so a run of n digits can be divided between them in O(n²) ways, and rejecting an input retries every division. Parsing is synchronous and uninterruptible, so a long malformed color string blocks the thread: | input | time to reject | | --- | --- | | 16 KB | 224 ms | | 64 KB | 4.4 s | | 128 KB | 18.5 s | Reachable through colord() and getFormat(), and through any method that accepts a color string — including isEqual(), mix() and contrast(). The affected matchers are parseRgbaString and parseHslaString (built in) and parseHwbaString, parseLchaString, parseCmykaString (plugins). Growth is polynomial, not exponential — multi-kilobyte payloads are required for a noticeable stall. Who is affected Applications that pass attacker-controlled strings of unbounded length to colord() — for example a server validating a color taken from a request body, JSON field,…

Published by the source

8 Sep 2026, 20:51 UTC

Last modified by the source

8 Sep 2026, 21:00 UTC

Source last checked

26 Oct 2026, 13:02 UTC

1. Revision 4 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-2wm5-q62r-hmrv

2. Revision 3 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-2wm5-q62r-hmrv

4. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-2wm5-q62r-hmrv

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# Patch Next advisory brief: CVE-2026-85062

Advisory: Colord: Slow rejection of oversized malformed color strings
IDs: CVE-2026-85062, GHSA-2wm5-q62r-hmrv
Record: https://patchnext.com/advisories/cve-2026-85062 (revision 4, source checked 26 Oct 2026, 13:02 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: colord 2.9.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm colord: affected < 2.9.4; fixed in 2.9.4

## Suggested inspection (read-only)
- `npm ls colord --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on colord.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2wm5-q62r-hmrv (GitHub-reviewed advisory GHSA-2wm5-q62r-hmrv lists affected ranges: npm colord >=0 <2.9.4)
- Verified: https://osv.dev/vulnerability/GHSA-2wm5-q62r-hmrv (OSV record GHSA-2wm5-q62r-hmrv lists affected ranges: npm colord >=0 <2.9.4 (fixed))

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