VulnerabilityPublished 10 Nov 2026

CVE-2026-125333: ReDoS in forge.http response header and cookie trimming

Affects node-forgeSource GCVE Database

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Authoritative record:CVE-2026-125333· Medium 5.9

Not known to be exploited · CVSS 5.9 Medium : upgrade to 1.4.3 when convenient.

Data as of 10 Nov 2026, 22:34 UTC

CVSS 3.1 base score

5.9Medium

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 3.1	5.9

Patch: Available – fixed in 1.4.3

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 10 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade node-forge to 1.4.3.

Affected software

Product	Affected	Fixed in
npmnode-forge	Affected >=0.1.2 <1.4.3	Fixed in 1.4.3

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

`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. `forge.http` is not loaded by `require('node-forge')`. It is part of the `forge.all` bundle and needs a socket pool provided by the application (historically Flash sockets via `forge.xhr`), so few applications use it. The fix trims trailing whitespace with a loop, as `lib/pem.js` has done since 1.4.1. The trimmed result is unchanged. #### Patches Fixed in node-forge 1.4.3. #### Workarounds Limit the size of HTTP response headers before passing them to `forge.http`, for example in the socket pool's data handler. #### Resources - Related: GHSA-7wch-p9px-956x (ReDoS in PEM decoding, fixed in 1.4.1): https://github.com/digitalbazaar/forge/security/advisories/GHSA-7wch-p9px-956x #### Severity CVSS 3.1: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H (5.9, Moderate) CVSS 4.0 (informational): CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N (8.2) CVSS 4.0 has no counterpart to 3.1's AC:H beyond AT:P and scores this higher; the severity rating follows CVSS 3.1. #### Credits Reported by @manus-pi. ### Proof of concept var response = forge.http.createResponse(); var ws = new Array(40001).join('\t '); response.readHeader(forge.util.createBuffer( 'HTTP/1.1 200 OK\r\nX-A: a' + ws + 'X\r\n\r\n')); // <= 1.4.2: about 4 seconds (quadratic in the whitespace length) // 1.4.3: about 1 ms Regression tests are in tests/security/ghsa-6cv4-p8m7-4r25.js. ### Impact Applications that use `forge.http` to talk to servers they don't control are affected. The server, or an on-path attacker, can send a response header that blocks the client's event loop for minutes, denying service to everything else in the process. There is no confidentiality or integrity impact.

CWE-1333Inefficient Regular Expression Complexity (opens in a new tab)
Base weaknessLikelihood of exploit: High
The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.
Architecture and Design
Use regular expressions that do not support backtracking, e.g. by removing nested quantifiers.
System Configuration
Set backtracking limits in the configuration of the regular expression implementation, such as PHP's pcre.backtrack_limit. Also consider limits on execution time for the process.
Implementation
Do not use regular expressions with untrusted input. If regular expressions must be used, avoid using backtracking in the expression.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
Regular Expression Exponential Blowup (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

WeaknessesCWE-1333

Technical details

References

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