CVE-2026-66746
Rouille 0.4.0 - 3.6.2 HTTP Response Splitting via Header Injection
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.
INFO
Published Date :
July 28, 2026, 4:20 p.m.
Last Modified :
Oct. 24, 2026, 1:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update Rouille to version 3.6.3 or later.
- Sanitize all user-controlled input before reflection.
- Validate and encode HTTP header values.
- Avoid direct interpolation of input into headers.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-66746.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-66746 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-66746
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-66746 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-66746 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 24, 2026
Action Type Old Value New Value Added Translation Title: rouille de tomaka, Description: Rouille 0.4.0 hasta 3.6.2 contiene una vulnerabilidad de división de respuesta HTTP que permite a atacantes remotos inyectar encabezados de respuesta arbitrarios incrustando bytes de retorno de carro (0x0D) o salto de línea (0x0A) en entradas controladas por el atacante. Los atacantes pueden explotar parámetros de consulta decodificados por porcentaje reflejados en los encabezados de respuesta o inyectar caracteres LF puros en valores de encabezado de cookie que se interpolan directamente en los encabezados de respuesta Set-Cookie, lo que permite el envenenamiento de caché, la fijación de sesión y ataques de anulación de encabezados de seguridad como eludir las políticas CSP o CORS. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 29, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-66746', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-29T13:50:09.794006Z'} -
New CVE Received by [email protected]
Jul. 28, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/tomaka/rouille', 'vendor': 'tomaka', 'product': 'rouille', 'versions': [{'status': 'affected', 'version': '0.4.0', 'versionType': 'semver', 'lessThanOrEqual': '3.6.2'}], 'packageURL': 'pkg:github/tomaka/rouille', 'defaultStatus': 'affected'}] Added 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. Added CVSS V4.0 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 Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N Added CWE CWE-113 Added Reference https://github.com/theopaid/HTTP-Response-Splitting-via-Unvalidated-Response-Header-Values-rouille- Added Reference https://www.vulncheck.com/advisories/rouille-http-response-splitting-via-header-injection