CVE-2026-55204
Last modified
CVE-2026-55204 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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.. EPSS estimates a 0.48% chance of exploitation in the next 30 days.
Description
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.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Haproxy | Haproxy | < 2.4.36 |
| Haproxy | Haproxy | >= 2.5, < 2.6.30 |
| Haproxy | Haproxy | >= 2.7, < 2.8.25 |
| Haproxy | Haproxy | >= 2.9, < 3.0.24 |
| Haproxy | Haproxy | >= 3.1, < 3.2.20 |
| Haproxy | Haproxy | >= 3.3, < 3.4.1 |
References
Timeline
- Published
- Last Modified
- Status
- Analyzed
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