CVE-2026-21710: nodejs node · Unthrottled Resource Allocation
Affects nodejs nodeSource CVE Database V5
Not known to be exploited · 25% EPSS · CVSS 7.5 High · fixed in 26.0.0 : patch nodejs node soon.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 25.4% chance of exploitation in 30 days – higher than 97% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 26.0.0, 25.0.0, 23.0.0 +1
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 30 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
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), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade nodejs node to 26.0.0, 25.0.0, 23.0.0 or 21.0.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| nodejsnode | Affected
| Fixed in– |
npmnodepkg:npm/nodeOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released security updates addressing this vulnerability in their Node.js packages. Applying the official patches from Red Hat advisories (e.g., RHSA-2026:7310 and related errata) will remediate the issue. Until patched, applications can mitigate the impact by wrapping all accesses to req.headersDistinct in try/catch blocks, though this is a workaround rather than a full fix. Users should consult the Red Hat advisories for detailed update instructions and apply the updates promptly.
Description
A flaw in Node.js HTTP request handling causes an uncaught `TypeError` when a request is received with a header named `__proto__` and the application accesses `req.headersDistinct`. When this occurs, `dest["__proto__"]` resolves to `Object.prototype` rather than `undefined`, causing `.push()` to be called on a non-array. This exception is thrown synchronously inside a property getter and cannot be intercepted by `error` event listeners, meaning it cannot be handled without wrapping every `req.headersDistinct` access in a `try/catch`. * This vulnerability affects all Node.js HTTP servers on **20.x, 22.x, 24.x, and v25.x**
References
- nodejs.org/en/blog/vulnerability/march-2026-security-releases (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-21710 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2453151 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-21710.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:7310 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:7080 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:7675 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:8339 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:7123 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:7670 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:9711 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:9874 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:7983 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:7896 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:7302 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:7350 (opens in a new tab)