CVE-2026-15711

HIGH
MEDIUM Priority: 0.06 BB Relevance: 75/100
Published: 2026-07-14 Modified: 2026-11-11 First seen: 2026-11-05 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Unchanged
C: None
I: None
A: High

Description

A vulnerability was found in libsoup's WebSocket frame parsing implementation. The library fails to validate length rules specified in RFC 6455 §5.5, which mandates that all WebSocket control frames (e.g., PING, PONG, CLOSE) contain a payload of 125 bytes or less. A remote, unauthenticated attacker can exploit this by sending a non-compliant, oversized control frame. Because the parser handles this protocol violation improperly instead of throwing an immediate connection termination error, it triggers a internal processing crash, resulting in a remote denial of service (DoS) for applications utilizing libsoup WebSockets.

References & Advisories (15)

https://access.redhat.com/errata/RHSA-2026:68234
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:68235
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:68266
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:68612
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:69108
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:69297
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:69863
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:70598
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:70599
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:71389
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:98453
vendor-advisory x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2499924
issue-tracking x_refsource_REDHAT

Bug Bounty Relevance

75 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

7.5 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploitation Probability

0.74%
Raw Score 0.007450
Percentile 55.4%
Date 2026-11-14

EPSS Trend

2026-11-14
0.00745
2026-11-13
0.00745
2026-11-12
0.00745
2026-11-10
0.00745
2026-11-09
0.00745
2026-11-08
0.00745
2026-11-07
0.00745
2026-11-06
0.00745
2026-11-05
0.00745

Intelligence Sources

mitre ref →
nvd ref →