CVE catalog
CVE-2026-18149
undici's retry handler can leave an already-exposed response body pending forever. When a server returns a successful response that declares a Content-Length, sends only part of the body, and closes t
- Severity
- Medium · CVSS 5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 0.48% · Oct 25, 2026
undici's retry handler can leave an already-exposed response body pending forever. When a server returns a successful response that declares a Content-Length, sends only part of the body, and closes the connection, the retry handler retries the request. If the retry returns a non-retryable status such as 400, the handler forwards that new response downstream and replaces its internal response stream, but the original response body that the application still holds is never ended or destroyed. As a result calls that read that body never settle, and the configured body timeout does not fire because its timer is tied to the connection parser rather than the orphaned body. An attacker-controlled server can trigger this with two short responses without keeping a connection open, and repeated requests accumulate pending promises and streams that can exhaust application concurrency or memory. This affects undici versions from 7.11.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | node-undici | sid | 8.12.2+dfsg+~cs3.2.3-2 | fixed |
| Debian | node-undici | forky | 8.10.2+dfsg+~cs3.2.2-1 | fixed |
| Debian | node-undici | trixie | 7.3.0+dfsg1+~cs24.12.11-1 | vulnerable |
| Debian | node-undici | bookworm | 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 | vulnerable |
| Debian | node-undici | bookworm-security | 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 | vulnerable |
| Cpe | undici | Not reported | 8.10.2 | fixed |
| Npm | undici | Not reported | 8.10.2 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | node-undici | source | sid | 8.10.2+dfsg+~cs3.2.2-1 | not yet assigned | Not reported | [1146745] |
| Debian | node-undici | source | forky | 8.10.2+dfsg+~cs3.2.2-1 | not yet assigned | Not reported | [1146745] |
| Debian | node-undici | source | trixie | (unfixed) | not yet assigned | Not reported | [1146745] |
| Debian | node-undici | source | bookworm | (unfixed) | not yet assigned | Not reported | [1146745] |
| Cpe | undici | cpe | Not reported | 8.10.2 | Not reported | NVD-CVE-2026-18149 | Not reported |
| Npm | undici | npm | Not reported | 8.10.2 | Not reported | GHSA-PMJH-FQ2X-6V4X | Not reported |
Notes
[trixie] node-undici: Minor issue [bookworm] node-undici: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [node-llhttp]Affected
Source package: [node-undici]
Details (4)
8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4· all · bookwormAffected
nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4· all · bookwormAffected
nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3· all · bookworm-securityAffected
nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3· all · bookworm-securityAffected
nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
- [node-undici]Affected
Details (4)
5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4· all · bookwormAffected
nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4· all · bookwormAffected
nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3· all · bookworm-securityAffected
nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3· all · bookworm-securityAffected
nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
[Debian 13 (Trixie)]
- [libllhttp9.2]Affected
Source package: [node-undici]
Details (2)
9.2.1~7.3.0+dfsg1+~cs24.12.11-1· amd64 · trixieAffected
nvd · node-undici · debian · 13
9.2.1~7.3.0+dfsg1+~cs24.12.11-1· arm64 · trixieAffected
nvd · node-undici · debian · 13
- [libllhttp-dev]Affected
Source package: [node-undici]
Details (2)
9.2.1~7.3.0+dfsg1+~cs24.12.11-1· amd64 · trixieAffected
nvd · node-undici · debian · 13
9.2.1~7.3.0+dfsg1+~cs24.12.11-1· arm64 · trixieAffected
nvd · node-undici · debian · 13
- [node-llhttp]Affected
Source package: [node-undici]
Details (2)
9.2.1~7.3.0+dfsg1+~cs24.12.11-1· all · trixieAffected
nvd · node-undici · debian · 13
9.2.1~7.3.0+dfsg1+~cs24.12.11-1· all · trixieAffected
nvd · node-undici · debian · 13
- [node-undici]Affected
Details (2)
7.3.0+dfsg1+~cs24.12.11-1· all · trixieAffected
nvd · node-undici · debian · 13
7.3.0+dfsg1+~cs24.12.11-1· all · trixieAffected
nvd · node-undici · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/]
- [https://github.com/advisories/GHSA-pmjh-fq2x-6v4x]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-18149]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-18149]
- [https://security-tracker.debian.org/tracker/CVE-2026-18149]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-18149.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-3596.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]