VulnerabilityDeferred

CVE-2026-104380

Punk versions from 0.48 before 0.55 for Perl route Extended CONNECT requests to any GET route without an Origin check in ps_serve_one.

MEDIUM 5.3EPSS 0.16%

Does this matter?

Lower severity and a low EPSS score (0.16%). Track it; it rarely justifies an emergency change on its own.

Description

Punk versions from 0.48 before 0.55 for Perl route Extended CONNECT requests to any GET route without an Origin check in ps_serve_one. On HTTP/2 and HTTP/3 a WebSocket handshake arrives as an Extended CONNECT, which is matched as a GET and so reaches every GET route, API operation and mount. The Origin check runs only when a websocket route matches. On this transport the handler's status is the handshake response, and a 2xx accepts it. A cross-origin page can open a WebSocket to any path and learn from its open or error event whether that path returns 2xx.

CVSS 3.1: 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS: 0.16% probability · 5th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-1385
Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e

EPSS trend

EPSS moved from 0.1% on 6 October 2026 to 0.2% on 26 October 2026.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.