Advertise listener shutdown via incomplete multicast datagram
Published Aug 19, 2026 · Updated Aug 20, 2026
NULL pointer dereference in Red Hat mod_cluster allows adjacent remote attackers to shut down proxy advertisement with a crafted datagram. AdvertiseListenerImpl passes absent Date, Digest, and Sequence header values to verifyDigest(), whose null dereference escapes the worker exception handler. One datagram on the advertisement multicast segment permanently stops that listener until restart, even when AdvertiseSecurityKey is configured.
Summary
What happened
NULL pointer dereference in Red Hat mod_cluster allows adjacent remote attackers to shut down proxy advertisement with a crafted datagram. AdvertiseListenerImpl passes absent Date, Digest, and Sequence header values to verifyDigest(), whose null dereference escapes the worker exception handler. One datagram on the advertisement multicast segment permanently stops that listener until restart, even when AdvertiseSecurityKey is configured.
The record
- CVE
- CVE-2026-76166
- Published
- Aug 19, 2026
- Updated
- Aug 20, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat JBoss Enterprise Application Platform Expansion Pack
- Classifications
- CWE-476, T1499
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 19, 2026CVE publishedPublication date reported by the CVE source.
- Aug 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo