CVE catalog
CVE-2026-40561
Starlet versions through 0.31 for Perl allows HTTP Request Smuggling via Improper Header Precedence. Starlet incorrectly prioritizes "Content-Length" over "Transfer-Encoding: chunked" when both heade
- Severity
- Medium · CVSS 5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.36% · Oct 25, 2026
Starlet versions through 0.31 for Perl allows HTTP Request Smuggling via Improper Header Precedence. Starlet incorrectly prioritizes "Content-Length" over "Transfer-Encoding: chunked" when both headers are present in an HTTP request. Per RFC 7230 3.3.3, Transfer-Encoding must take precedence. An attacker could exploit this to smuggle malicious HTTP requests via a front-end reverse proxy.
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 | starlet | sid | 0.32-1 | fixed |
| Debian | starlet | forky | 0.32-1 | fixed |
| Debian | starlet | trixie | 0.31-2+deb13u1 | fixed |
| Debian | starlet | bookworm | 0.31-2 | vulnerable |
| Cpe | starlet | Not reported | Not reported | vulnerable |
| Cpe | starlet | Not reported | Not reported | unknown |
| Cpe | starlet | Not reported | Not reported | unknown |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | starlet | source | sid | 0.31-3 | not yet assigned | Not reported | [1135584] |
| Debian | starlet | source | forky | 0.31-3 | not yet assigned | Not reported | [1135584] |
| Debian | starlet | source | trixie | 0.31-2+deb13u1 | not yet assigned | Not reported | [1135584] |
| Debian | starlet | source | bookworm | (unfixed) | not yet assigned | Not reported | [1135584] |
Notes
[bookworm] starlet: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [starlet]Affected
Details (2)
0.31-2· all · bookwormAffected
nvd · starlet · debian · bookworm; nvd · starlet · debian · 12
0.31-2· all · bookwormAffected
nvd · starlet · debian · bookworm; nvd · starlet · debian · 12
[Debian 13 (Trixie)]
- [starlet]Fixed
Details (2)
0.31-2+deb13u1· all · trixieFixed · Fixed:
0.31-2+deb13u1nvd · starlet · debian · 13
0.31-2+deb13u1· all · trixieFixed · Fixed:
0.31-2+deb13u1nvd · starlet · debian · 13
Observed:
References
- [http://www.openwall.com/lists/oss-security/2026/05/03/1]
- [https://datatracker.ietf.org/doc/html/rfc7230#section-3.3.3]
- [https://github.com/kazuho/Starlet/commit/a7d5dfd1862aafa43e5eaca0fdb6acf4cc15b2d0.patch]
- [https://metacpan.org/release/KAZUHO/Starlet-0.32/changes]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-40561]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-40561]
- [https://security-tracker.debian.org/tracker/CVE-2026-40561]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database]