Bug 2490518 (CVE-2026-55204) - CVE-2026-55204 haproxy: HAProxy: Denial of Service via HPACK dynamic table insertions
Summary: CVE-2026-55204 haproxy: HAProxy: Denial of Service via HPACK dynamic table in...
Keywords:
Status: NEW
Alias: CVE-2026-55204
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2501072
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-18 17:02 UTC by OSIDB Bzimport
Modified: 2026-07-16 06:57 UTC (History)
12 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-06-18 17:02:09 UTC 
HAProxy through  3.4.0, fixed in commit 9a6d1fe, contains a null pointer dereference vulnerability in hpack_dht_insert() within src/hpack-tbl.c that fails to validate the return value of hpack_dht_defrag() when the memory pool is exhausted. An attacker can trigger HPACK dynamic table insertions under memory pressure to dereference a NULL pointer and crash HAProxy worker processes, causing denial of service.
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