CVE-2026-66746

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 61/100
Published: 2026-07-28 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: Passive
S: X
AT: None
VC: Low
VI: Low
VA: None

Description

Rouille 0.4.0 through 3.6.2 contains an HTTP response splitting vulnerability that allows remote attackers to inject arbitrary response headers by embedding carriage return (0x0D) or line feed (0x0A) bytes into attacker-controlled input. Attackers can exploit percent-decoded query parameters reflected into response headers or inject bare LF characters into Cookie header values that are interpolated directly into Set-Cookie response headers, enabling cache poisoning, session fixation, and security header override attacks such as bypassing CSP or CORS policies.

Weakness Classification (1)

Bug Bounty Relevance

61 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity

CVSS Score

5.3 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/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

EPSS — Exploitation Probability

0.34%
Raw Score 0.003400
Percentile 27.5%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00340
2026-10-28
0.00340

Intelligence Sources

nvd ref →