CVE-2026-125333: Forge denial of service via headers

Summary

Forge (node-forge), a JavaScript TLS library, has a regular-expression flaw in its forge.http module that affects versions before 1.4.3 when it is used with a socket pool to talk to an untrusted server. A malicious server or on-path attacker can send a crafted response header from the network, without logging in, to freeze a Node.js process or browser tab for a long time, causing a denial of service.

Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.

Read the original description

Forge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. From 0.1.2 until 1.4.3, forge.http uses _trimString() in lib/http.js to remove trailing whitespace from response header values and cookie names and values with a regular expression that can take quadratic time. A malicious server or on-path attacker can supply a long whitespace run followed by a non-whitespace character in a response header, causing response.readHeader() or response.getCookies() to repeatedly scan the input and block the Node.js event loop or browser tab for minutes. Applications are affected only when they use forge.http with a socket pool to communicate with an untrusted server; forge.http is not loaded by require('node-forge'), and the issue has no confidentiality or integrity impact. This issue is fixed in version 1.4.3.

cve.now Index

58Pcve.now Index 58 of 100 · methodology v3 · provisional

Exploitation15/40CISA rates a proof of concept as public
Exposure17/25No login or user action needed per the CVSS vector, reachable over the network without a login · Unknown: No advisory context yet
Reach20/20node-forge: 55.6M downloads a week
Severity5.9/10CVSS 5.9
No patch0/5No signal

What would change the score

Would score about 88 if added to CISA KEV
Would score about 83 if CISA's SSVC rates exploitation active
Would score about 63 if advisories confirm default setups are exposed

How the score works · Rankings

Impact

Widely used
node-forge has 55.6m weekly downloads.Source: npmjs.com
64.9k packages depend on node-forge.Source: deps.dev

What to do

Upgrade to a fixed version: 1.4.3.

Check your systems with an agent

Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.

Check whether my systems are affected by CVE-2026-125333 (Forge: ReDoS in forge.http response header and cookie trimming), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-125333 (entry last updated 2026-11-10):
Affected:
- digitalbazaar forge: from 0.1.2, fixed in 1.4.3
- npm package node-forge: from 0.1.2, fixed in 1.4.3
Fixed versions: 1.4.3.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-125333 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-125333 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Packages (npm): find every lockfile in each project and run check_stack from the cve.now MCP server on each one. Compare the resolved versions, not the ranges a manifest declares, with the affected versions above. Include transitive dependencies.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/digitalbazaar/forge/security/advisories/GHSA-6cv4-p8m7-4r25
- https://github.com/digitalbazaar/forge/pull/1169
- https://github.com/digitalbazaar/forge/commit/326a4d0903ee46358bc849a5c3fd96d9c21489bd
- https://github.com/digitalbazaar/forge/releases/tag/v1.4.3
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Entry: https://cve.now/CVE-2026-125333
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-125333.

Timeline

Nov 10, 2026, 6:48 PM UTCCVE published
Nov 10, 2026, 8:54 PM UTCFirst seen by cve.now
Nov 10, 2026, 9:00 PM UTCCISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: partial
Nov 10, 2026, 9:01 PM UTCRecord last updated

Affected versions

digitalbazaar forge
From 0.1.2 · fixed in 1.4.3
node-forgenpm
From 0.1.2 · fixed in 1.4.3
Fixed in 1.4.3 (released Nov 4, 2026, 6 days before disclosure).
The latest release, 1.4.3, is not affected.

Evidence 6

Vendor advisory · 1

Establishes: Affected and fixed versions.

Advisory
GitHub · digitalbazaar/forge · Advisory GHSA-6cv4-p8m7-4r25

CVE record · 2

Establishes: The identifier and description.

Record
CVE List · CVE-2026-125333
Record
NVD · CVE-2026-125333

Corrections

None so far.

Something wrong on this page? Report an error. Every fix is listed here.

Questions about CVE-2026-125333

Is CVE-2026-125333 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. CISA's SSVC assessment notes a proof of concept exists. No public exploit code is tracked.Source: cve.now feed data

Which versions are affected by CVE-2026-125333?

forge: from 0.1.2 before 1.4.3. node-forge (npm): from 0.1.2 before 1.4.3.Source: cve.now feed data

How do I fix CVE-2026-125333?

Upgrade to a fixed version: 1.4.3.Source: cve.now feed data

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