CVE-2026-40562 json
Gazelle versions through 0.49 for Perl allows HTTP Request Smuggling via Improper Header Precedence
published 2026-05-06 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-27825
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 25%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 6 mo ago
Exploit prediction
0.32% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
Affected products
- KAZEBURO Gazelle
Classification
- Weakness
-
- CWE-444 Inconsistent Interpretation of HTTP Requests
References
-
security.metacpan.org
/patches/G/Gazelle/0.49/CVE-2026-40562-r1.patch
patch
-
datatracker.ietf.org
/doc/html/rfc7230#section-3.3.3
third-party-advisory
-
metacpan.org
/release/KAZEBURO/Gazelle-0.50/changes
release-notes
-
openwall.com
/lists/oss-security/2026/05/06/7
mailing-list, third-party-advisory
Sources
- CVE List CVE-2026-40562
- NVD CVE-2026-40562
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