CVE-2026-40562
Gazelle versions through 0.49 for Perl allows HTTP Request Smuggling via Improper Header Precedence.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.32%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Gazelle versions through 0.49 for Perl allows HTTP Request Smuggling via Improper Header Precedence. Gazelle 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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.32% probability · 25th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-444
- Affected
- kazeburo/gazelle
- Source
- 9b29abf9-4ab0-4765-b253-1875cd9b441e
References
- https://datatracker.ietf.org/doc/html/rfc7230#section-3.3.3Third Party Advisory
- https://metacpan.org/release/KAZEBURO/Gazelle-0.50/changesRelease Notes
- https://security.metacpan.org/patches/G/Gazelle/0.49/CVE-2026-40562-r1.patchPatch
- http://www.openwall.com/lists/oss-security/2026/05/06/7Mailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.