GHSA-vxpw-j846-p89q
undici WebSocket client vulnerable to denial of service via fragment count bypass
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
## Impact
The undici WebSocket client enforces `maxPayloadSize` on the cumulative byte count of fragments in a message but does not enforce a limit on the number of fragments. A malicious WebSocket server can stream many small or empty continuation frames that each pass per-frame and cumulative-size validation, collectively causing unbounded memory growth in the client process. The result is memory exhaustion and a denial of service.
Affected applications are those using the undici WebSocket client (`new WebSocket(...)`) or the `WebSocketStream` API that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint.
All releases starting at undici 6.17.0 are affected.
## Patches
Upgrade to undici v6.27.0, v7.28.0 or v8.5.0.
## Workarounds
No workaround is available. The fix must be applied through an upgrade.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/nodejs/undici/security/advisories/GHSA-vxpw-j846-p89q
- https://nvd.nist.gov/vuln/detail/CVE-2026-12151
- https://github.com/nodejs/undici/commit/32dbf0b3dd93daf6d87badf506d52e89f2e20e78
- https://access.redhat.com/errata/RHSA-2026:34342
- https://access.redhat.com/errata/RHSA-2026:56431
- https://access.redhat.com/errata/RHSA-2026:57013
- https://access.redhat.com/errata/RHSA-2026:60520
- https://access.redhat.com/errata/RHSA-2026:62260
- https://access.redhat.com/errata/RHSA-2026:65126
- https://access.redhat.com/errata/RHSA-2026:66488
- https://access.redhat.com/errata/RHSA-2026:66545
- https://access.redhat.com/security/cve/CVE-2026-12151
- https://bugzilla.redhat.com/show_bug.cgi?id=2489980
- https://cna.openjsf.org/security-advisories.html
- https://github.com/nodejs/undici
- https://github.com/nodejs/undici/releases/tag/v6.27.0
- https://github.com/nodejs/undici/releases/tag/v7.28.0
- https://github.com/nodejs/undici/releases/tag/v8.5.0
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12151.json
- https://access.redhat.com/errata/RHSA-2026:35841
- https://access.redhat.com/errata/RHSA-2026:35842
- https://access.redhat.com/errata/RHSA-2026:35891
- https://access.redhat.com/errata/RHSA-2026:35892
- https://access.redhat.com/errata/RHSA-2026:36621
- https://access.redhat.com/errata/RHSA-2026:36754
- https://access.redhat.com/errata/RHSA-2026:36820
- https://access.redhat.com/errata/RHSA-2026:38009
- https://access.redhat.com/errata/RHSA-2026:38236
- https://access.redhat.com/errata/RHSA-2026:39246
- https://access.redhat.com/errata/RHSA-2026:39868
- https://access.redhat.com/errata/RHSA-2026:41929
- https://access.redhat.com/errata/RHSA-2026:41947
- https://access.redhat.com/errata/RHSA-2026:47728
- https://access.redhat.com/errata/RHSA-2026:48124
- https://access.redhat.com/errata/RHSA-2026:48151
- https://access.redhat.com/errata/RHSA-2026:52399
- https://access.redhat.com/errata/RHSA-2026:56366