CVE-2026-123868: Nodejs · An unauthenticated HTTP/2 client can exhaust Node.js server memory because inbound DATA
Affects nodejsSource GCVE Database
Not known to be exploited · CVSS 5.9 Medium.
Data as of 13 Nov 2026, 22:04 UTC
Thin evidence
One scorer or none| CNA (openjs) | CVSS 3.0 | 5.9 |
|---|
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/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
An unauthenticated HTTP/2 client can exhaust Node.js server memory because inbound DATA queued on an undrained stream is charged to no session budget. Each inbound DATA frame creates one JavaScript Buffer view in the receiving stream's readable queue, but nothing charges that queue to current_session_memory_: the socket read buffer is accounted only during parsing and released immediately, so whatever stays queued is accounted to nothing. A peer that fills a stream's receive window with one-byte DATA frames pays about 10 wire bytes per frame while the server retains about 114 bytes per frame, so a single stream on one connection can retain hundreds of megabytes from tens of megabytes sent. maxSessionMemory neither bounds the growth nor refuses new streams, because Http2Session::CanAddStream gates admission on the same counter that never sees the queue. This vulnerability affects Node.js 26.x and 24.x.
References
- ubuntu.com/security/CVE-2026-123868 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-123868 (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)