# CVE-2026-123868: Node.js is vulnerable to an HTTP/2 memory exhaustion denial of service via unaccounted inbound DATA on an undrained stream

Status: published. Published: 2026-11-11. Updated: 2026-11-11.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- nodejs / node: ≥ 24.0.0; < 24.22.3 (affected, semver); ≥ 25.0.0; < 26.13.1 (affected, semver). Source: CNA: openjs

## Severity and prioritization

- CVSS 3.0: 5.9 (medium); CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H; source: CNA: openjs

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-400

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://nodejs.org/en/blog/vulnerability/november-2026-security-releases (CNA: openjs; vendor-advisory)

- https://cna.openjsf.org/security-advisories.html (CNA: openjs)

## Provenance

- CNA: openjs: https://www.cve.org/CVERecord?id=CVE-2026-123868; retrieved 2026-11-11; source updated 2026-11-11

Revision: 86e25db19da9f242fd6008650ec1b06cb52ddc4e2db125c312c10e18b60c6432

Canonical: https://y2.dev/cve/CVE-2026-123868

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