CVE-2026-66754

high

Description

Rouille 0.1.6 through 3.6.2 contains a reachable assertion vulnerability in the Request::remove_prefix function that allows remote unauthenticated attackers to crash the server by sending a crafted percent-encoded URL. Attackers can send a request whose decoded path matches a configured prefix while the raw percent-encoded path does not, causing the assert! to fail and triggering either a 500 error or full process termination depending on the panic configuration.

References

https://www.vulncheck.com/advisories/rouille-reachable-assertion-dos-via-remove-prefix-percent-encoding

https://github.com/theopaid/Remote-Denial-of-Service-via-Reachable-Assertion-in-URL-Prefix-Handling-rouille-

Details

Source: Mitre, NVD

Published: 2026-07-28

Updated: 2026-07-28

Risk Information

CVSS v2

Base Score: 5.4

Vector: CVSS2#AV:N/AC:H/Au:N/C:N/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 5.9

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: Medium

CVSS v4

Base Score: 8.2

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Severity: High