Forge: ReDoS in forge.http response header and cookie trimming

Exploitation

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

CVSS

5.9 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

`forge.http` trims response header and `Set-Cookie` values with the regular expression `/\s*$/`, which takes quadratic time on a long run of whitespace followed by another character. A server or on-path attacker can block a `forge.http` client for minutes with one large response header. Fixed in node-forge 1.4.3.

Details `_trimString()` in `lib/http.js` removes trailing whitespace with `str.replace(/\s*$/, '')`. On a string of n whitespace characters followed by a non-whitespace character, the regular expression engine tries a match at each of the n positions and scans the rest of the run each time, so the work is O(n^2). `forge.http` calls `_trimString()` on every response header value read by `response.readHeader()`, and again on cookie names and values in `response.getCookies()`. There is no limit on header size. With Node.js 24, an 80 KB header value takes about 4 seconds to parse, and 1 MB about 10 minutes, during which the event loop (or browser tab) is blocked.…

Published by the source

10 Nov 2026, 21:16 UTC

Last modified by the source

10 Nov 2026, 21:30 UTC

Source last checked

11 Nov 2026, 06:00 UTC

1. Revision 2 · amended · 11 Nov 2026

   Amended from osv record GHSA-6cv4-p8m7-4r25

2. Revision 1 · created · 10 Nov 2026

   Published from ghsa record GHSA-6cv4-p8m7-4r25

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# Patch Next advisory brief: CVE-2026-125333

Advisory: Forge: ReDoS in forge.http response header and cookie trimming
IDs: CVE-2026-125333, GHSA-6cv4-p8m7-4r25
Record: https://patchnext.com/advisories/cve-2026-125333 (revision 2, source checked 11 Nov 2026, 06:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: node-forge 1.4.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm node-forge: affected >= 0.1.2, < 1.4.3; fixed in 1.4.3

## Suggested inspection (read-only)
- `npm ls node-forge --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 node-forge.
- 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-6cv4-p8m7-4r25 (GitHub-reviewed advisory GHSA-6cv4-p8m7-4r25 lists affected ranges: npm node-forge >=0.1.2 <=1.4.2)
- Verified: https://osv.dev/vulnerability/GHSA-6cv4-p8m7-4r25 (OSV record GHSA-6cv4-p8m7-4r25 lists affected ranges: npm node-forge >=0.1.2 <1.4.3 (fixed))

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