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TI-2026-47402 Aliases CVE-2026-66754GHSA-mrg5-7f6c-r28q

Rouille 0.1.6 - 3.6.2 Reachable Assertion DoS via remove_prefix percent-encoding

Priority HIGH 69CWE-617Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-617.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00565 47th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
tomakarouille0.1.6 – 3.6.2—No fix listedCNA
  • rouille Vendortomaka Affected 0.1.6 – 3.6.2 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-66754
  2. 2026-10-03 Alias added: GHSA-mrg5-7f6c-r28q

References

Exploit 1

  • TI-2026-47509 Rouille 0.3.3 - 3.6.2 HTTP Request Smuggling via proxy Header Injection CVSS 4.0MEDIUM 6.9
  • TI-2026-47508 Rouille 0.3.3 - 3.6.2 HTTP Request Smuggling via proxy Transfer-Encoding Header CVSS 4.0MEDIUM 6.3
  • TI-2026-47394 Rouille 0.4.0 - 3.6.2 HTTP Response Splitting via Header Injection CVSS 4.0MEDIUM 5.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences