CVE-2026-76166

MEDIUM
MEDIUM Priority: 0.10 BB Relevance: 54/100
Published: 2026-08-19 Modified: 2026-11-10 First seen: 2026-11-03 Status: active

Attack Surface

Adjacent Low Complexity No Auth No Interaction

CVSS Vector Breakdown

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

Description

A flaw was found in mod_cluster's AdvertiseListenerImpl (org.jboss.modcluster core module). A single crafted UDP multicast datagram with a valid HTTP status line and a "Server:" header but without the "Date:", "Digest:", and "Sequence:" headers triggers a NullPointerException in verifyDigest() that is not caught by the worker thread's exception handler. This causes the advertise listener thread to terminate permanently. The failure is silent (isListening() continues to return true) and persists until the node is restarted. The crash occurs before the AdvertiseSecurityKey comparison, so deployments with a configured security key are still affected.

Weakness Classification (1)

References & Advisories (6)

https://access.redhat.com/errata/RHSA-2026:93618
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:93622
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:96229
vendor-advisory x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2510883
issue-tracking x_refsource_REDHAT

Bug Bounty Relevance

54 / 100
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

4.3 / 10.0 v3.1
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS — Exploitation Probability

2.40%
Raw Score 0.023990
Percentile 84.3%
Date 2026-11-14

EPSS Trend

2026-11-14
0.02399
2026-11-13
0.02399
2026-11-12
0.02399
2026-11-10
0.02399
2026-11-09
0.02718
2026-11-08
0.02718
2026-11-07
0.02718
2026-11-06
0.02718
2026-11-05
0.02718
2026-11-04
0.02718
2026-11-03
0.01034

Intelligence Sources

mitre ref →
nvd ref →