CVE-2026-67182

Rouille 0.3.3 through 3.6.2 contains an HTTP request smuggling vulnerability that allows remote attackers to bypass access controls by injecting bare line feed characters (0x0A) into client-supplied request header values that are copied verbatim to upstream connections without validation. Attackers can craft a header value containing a complete additional HTTP request that is interpreted as a separate request by backends such as Go net/http and Python http.server, causing the backend to process a smuggled request with attacker-chosen method, path, and headers that bypasses the rouille handler's access control logic.

CVSS v4.0

6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:H/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1

7.5 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:L

EPSS

0.41% chance of exploitation in the next 30 days, 35th percentile

Published

2026-07-28

Proof-of-concept exploits (1)

• theopaid/HTTP-Request-Smuggling-Enables-Front-End-Access-Control-Bypass-rouille-0★ · 2026-07-28

References

• CVE Record
• NVD entry

Related

• CVE-2023-27163
• CVE-2026-66729
• CVE-2026-66730
• CVE-2026-66731
• CVE-2026-66746
• CVE-2026-66748