CVE-2026-123863: Nodejs · A reachable assertion in Node.js HTTP/2 session teardown lets any unauthenticated client
Affects nodejsSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 8.2 High.
Data as of 13 Nov 2026, 22:04 UTC
Thin evidence
One scorer or none| CNA (openjs) | CVSS 3.0 | 8.2 |
|---|
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 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 13 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10nodejspkg:deb/ubuntu/nodejs?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSnodejspkg:deb/ubuntu/nodejs?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSnodejspkg:deb/ubuntu/nodejs?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu Pro 22.04 LTSnodejspkg:deb/ubuntu/nodejs?arch=source&distro=esm-apps/jammyOther threats | Affected
| Fixed in– |
Ubuntu Pro 20.04 LTSnodejspkg:deb/ubuntu/nodejs?arch=source&distro=esm-apps/focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTSnodejspkg:deb/ubuntu/nodejs?arch=source&distro=esm-apps/bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
A reachable assertion in Node.js HTTP/2 session teardown lets any unauthenticated client abort the server, over both TLS and cleartext. A client can arrange for an Http2Stream that still holds nghttp2-allocated header buffers to outlive its session: the stream is removed from the session's stream set but never detached, so when ~Http2Session() runs the memory accounting is nonzero and the CHECK_EQ(current_nghttp2_memory_, 0) assertion fails, terminating the process. The trigger needs only a default http2 server whose handler responds before the request body has ended, which is typical. It is a variant of CVE-2024-27983 that the earlier fix did not cover, because that fix only detached streams still tracked in the session. This vulnerability affects Node.js 26.x (since 26.9.0) and 24.x (since 24.22.0).
References
- ubuntu.com/security/CVE-2026-123863 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-123863 (opens in a new tab)
- nodejs.org/en/blog/vulnerability/november-2026-security-releases (opens in a new tab)
- cna.openjsf.org/security-advisories.html (opens in a new tab)
- nodejs.org/en/blog/vulnerability/november-2026-security-releases (opens in a new tab)