CVE-2026-85024undici vulnerable to Denial of Service via unhandled error in WebSocket permessage-deflate decompression
Updated under an hour ago ()
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It affects undici and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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undici bundles a WebSocket client whose permessage-deflate size-limit cleanup removes all listeners from the internal zlib inflate stream, including its error listener, while that stream can still emit. When a remote peer sends a compressed payload that crosses the built-in 128 MiB decompressed-payload limit and then contains a malformed DEFLATE byte, the inflate stream emits a data error with no listener attached, which Node.js treats as a fatal unhandled error and terminates the entire process. Exploitation is remote and unauthenticated, requires no application mistake, and is asymmetric, since roughly 130 KB on the wire expands past the limit and crashes the process, and reconnecting can repeat the crash. This affects undici versions from 6.25.0 up to 6.28.1, from 7.28.0 up to 7.29.1, and from 8.1.0 up to 8.10.2. Users should upgrade to undici 6.28.1, 7.29.1, or 8.10.2.
- CVSS
- 5.9 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-248
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- openjs
- NVD analysis
- Analyzed
- Record last updated
- Sep 4, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
undici undici undici:undici (from the name) | from 6.25.0 before 6.28.1; 6.28.1 not affected; from 7.28.0 before 7.29.1; 7.29.1 not affected; from 8.1.0 before 8.10.2; 8.10.2 not affected | CNA record |
nodejs undici nodejs:undici | from 6.25.0 before 6.28.1; from 7.28.0 before 7.29.1; from 8.1.0 before 8.10.2 | NVD |
References
- https://github.com/nodejs/undici/security/advisories/GHSA-3wwx-pv8p-q78vvendor-advisory
- https://cna.openjsf.org/security-advisories.htmlvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.