Modcluster-core: mod_cluster advertise listener: unauthenticated dos via crafted multicast datagram
cve-program · CVE-2026-76166
PublishedA 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.
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cve-program · CVE-2026-76166
PublishedModcluster-core: mod_cluster advertise listener: unauthenticated dos via crafted multicast datagram
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.
- Source published
- 19 Aug 2026 10:01:28 UTC
- Source modified
- 9 Nov 2026 23:15:27 UTC
- Saved here
- 10 Nov 2026 01:02:45 UTC
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CVSS 3.1 · 4.3 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L