CVE-2026-55204

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Source
https://cve.org/CVERecord?id=CVE-2026-55204
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-55204.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-55204
Aliases
Downstream
Related
Published
2026-06-18T16:05:52.058Z
Modified
2026-07-21T18:30:06.017981045Z
Severity
  • 8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
HAProxy - NULL Pointer Dereference in hpack_dht_insert Function
Details

HAProxy through 3.4.0, fixed in commit 9a6d1fe, contains a null pointer dereference vulnerability in hpackdhtinsert() within src/hpack-tbl.c that fails to validate the return value of hpackdhtdefrag() 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.

Database specific 
{
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
        "CWE-476"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55204.json"
}
References

Affected packages

Git / github.com/haproxy/haproxy

Affected ranges

Type
GIT
Repo
https://github.com/haproxy/haproxy
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
9a6d1fe3f00d86ab4ea6ea6ea0a5d48fc058a513
Database specific 
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "last_affected": "3.4.0"
        }
    ],
    "cpe": "cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*",
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Affected versions

v1.*
v1.0.0
v1.0.1
v1.0.2
v1.1.0
v1.1.1
v1.1.10
v1.1.11
v1.1.12
v1.1.13
v1.1.14
v1.1.15
v1.1.16
v1.1.17
v1.1.18
v1.1.19
v1.1.2
v1.1.20
v1.1.21
v1.1.22
v1.1.23
v1.1.24
v1.1.25
v1.1.26
v1.1.27
v1.1.3
v1.1.4
v1.1.5
v1.1.6
v1.1.7
v1.1.8
v1.1.9
v1.2.0
v1.2.1
v1.2.1-pre1
v1.2.1-pre2
v1.2.1-pre3
v1.2.10
v1.2.10.1
v1.2.11
v1.2.11.1
v1.2.12
v1.2.13
v1.2.13.1
v1.2.14
v1.2.2
v1.2.3
v1.2.4
v1.2.5
v1.2.5-pre1
v1.2.5-pre2
v1.2.5-pre3
v1.2.5-pre4
v1.2.5.1
v1.2.5.2
v1.2.6
v1.2.6-pre4
v1.2.6-pre5
v1.2.7
v1.2.7.1
v1.2.7rc
v1.2.8
v1.2.9
v1.3.0
v1.3.1
v1.3.10
v1.3.10.1
v1.3.10.2
v1.3.11
v1.3.11.1
v1.3.11.2
v1.3.11.3
v1.3.11.4
v1.3.12
v1.3.13
v1.3.14
v1.3.15
v1.3.16
v1.3.16-rc1
v1.3.16-rc2
v1.3.17
v1.3.18
v1.3.2
v1.3.3
v1.3.4
v1.3.5
v1.3.6
v1.3.6.1
v1.3.7
v1.3.8
v1.3.8.1
v1.3.8.2
v1.3.9
v1.4-dev0
v1.4-dev1
v1.4-dev2
v1.4-dev3
v1.4-dev4
v1.4-dev5
v1.4-dev6
v1.4-dev7
v1.4-dev8
v1.4-rc1
v1.4.0
v1.4.1
v1.4.2
v1.4.3
v1.4.4
v1.4.5
v1.4.6
v1.5-dev10
v1.5-dev12
v1.5-dev13
v1.5-dev14
v1.5-dev15
v1.5-dev16
v1.5-dev17
v1.5-dev18
v1.5-dev19
v1.5-dev20
v1.5-dev21
v1.5-dev22
v1.5-dev23
v1.5-dev24
v1.5-dev25
v1.5-dev26
v1.5-dev8
v1.5-dev9
v1.5.0
v1.6-dev0
v1.6-dev1
v1.6-dev2
v1.6-dev3
v1.6-dev4
v1.6-dev5
v1.6-dev6
v1.6-dev7
v1.6.0
v1.7-dev0
v1.7-dev1
v1.7-dev2
v1.7-dev3
v1.7-dev4
v1.7-dev5
v1.7-dev6
v1.7.0
v1.8-dev0
v1.8-dev1
v1.8-dev2
v1.8-dev3
v1.8-rc1
v1.8-rc2
v1.8-rc3
v1.8-rc4
v1.8.0
v1.9-dev0
v1.9-dev1
v1.9-dev10
v1.9-dev11
v1.9-dev2
v1.9-dev3
v1.9-dev4
v1.9-dev5
v1.9-dev6
v1.9-dev7
v1.9-dev8
v1.9-dev9
v1.9.0
v2.*
v2.0-dev0
v2.0-dev1
v2.0-dev2
v2.0-dev3
v2.0-dev4
v2.0-dev5
v2.0-dev6
v2.0-dev7
v2.0.0
v2.1-dev0
v2.1-dev1
v2.1-dev2
v2.1-dev3
v2.1-dev4
v2.1-dev5
v2.1.0
v2.2-dev0
v2.2-dev1
v2.2-dev10
v2.2-dev11
v2.2-dev12
v2.2-dev2
v2.2-dev3
v2.2-dev4
v2.2-dev5
v2.2-dev6
v2.2-dev7
v2.2-dev8
v2.2-dev9
v2.2.0
v2.3-dev0
v2.3-dev1
v2.3-dev2
v2.3-dev3
v2.3-dev4
v2.3-dev5
v2.3-dev6
v2.3-dev7
v2.3-dev8
v2.3-dev9
v2.3.0
v2.4-dev0
v2.4-dev1
v2.4-dev10
v2.4-dev11
v2.4-dev12
v2.4-dev13
v2.4-dev14
v2.4-dev15
v2.4-dev16
v2.4-dev17
v2.4-dev18
v2.4-dev19
v2.4-dev2
v2.4-dev3
v2.4-dev4
v2.4-dev5
v2.4-dev6
v2.4-dev7
v2.4-dev8
v2.4-dev9
v2.4.0
v2.5-dev0
v2.5-dev1
v2.5-dev10
v2.5-dev11
v2.5-dev12
v2.5-dev13
v2.5-dev14
v2.5-dev15
v2.5-dev2
v2.5-dev3
v2.5-dev4
v2.5-dev5
v2.5-dev6
v2.5-dev7
v2.5-dev8
v2.5-dev9
v2.5.0
v2.6-dev0
v2.6-dev1
v2.6-dev10
v2.6-dev11
v2.6-dev12
v2.6-dev2
v2.6-dev3
v2.6-dev4
v2.6-dev5
v2.6-dev6
v2.6-dev7
v2.6-dev8
v2.6-dev9
v2.6.0
v2.7-dev0
v2.7-dev1
v2.7-dev10
v2.7-dev2
v2.7-dev3
v2.7-dev4
v2.7-dev5
v2.7-dev6
v2.7-dev7
v2.7-dev8
v2.7-dev9
v2.7.0
v2.8-dev0
v2.8-dev1
v2.8-dev10
v2.8-dev11
v2.8-dev12
v2.8-dev13
v2.8-dev2
v2.8-dev3
v2.8-dev4
v2.8-dev5
v2.8-dev6
v2.8-dev7
v2.8-dev8
v2.8-dev9
v2.8.0
v2.9-dev0
v2.9-dev1
v2.9-dev10
v2.9-dev11
v2.9-dev12
v2.9-dev2
v2.9-dev3
v2.9-dev4
v2.9-dev5
v2.9-dev6
v2.9-dev7
v2.9-dev8
v2.9-dev9
v2.9.0
v3.*
v3.0-dev0
v3.0-dev1
v3.0-dev10
v3.0-dev11
v3.0-dev12
v3.0-dev13
v3.0-dev2
v3.0-dev3
v3.0-dev4
v3.0-dev5
v3.0-dev6
v3.0-dev7
v3.0-dev8
v3.0-dev9
v3.0.0
v3.1-dev0
v3.1-dev1
v3.1-dev10
v3.1-dev11
v3.1-dev12
v3.1-dev13
v3.1-dev14
v3.1-dev2
v3.1-dev3
v3.1-dev4
v3.1-dev5
v3.1-dev6
v3.1-dev7
v3.1-dev8
v3.1-dev9
v3.1.0
v3.2-dev0
v3.2-dev1
v3.2-dev10
v3.2-dev11
v3.2-dev12
v3.2-dev13
v3.2-dev14
v3.2-dev15
v3.2-dev16
v3.2-dev17
v3.2-dev2
v3.2-dev3
v3.2-dev4
v3.2-dev5
v3.2-dev6
v3.2-dev7
v3.2-dev8
v3.2-dev9
v3.2.0
v3.3-dev0
v3.3-dev1
v3.3-dev10
v3.3-dev11
v3.3-dev12
v3.3-dev13
v3.3-dev14
v3.3-dev2
v3.3-dev3
v3.3-dev4
v3.3-dev5
v3.3-dev6
v3.3-dev7
v3.3-dev8
v3.3-dev9
v3.3.0
v3.4-dev0
v3.4-dev1
v3.4-dev10
v3.4-dev11
v3.4-dev12
v3.4-dev13
v3.4-dev14
v3.4-dev2
v3.4-dev3
v3.4-dev4
v3.4-dev5
v3.4-dev6
v3.4-dev7
v3.4-dev8
v3.4-dev9
v3.4.0
v3.5-dev0

Database specific

vanir_signatures_modified 
"2026-07-18T08:15:53Z"
source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-55204.json"
vanir_signatures 
[
    {
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/haproxy/haproxy/commit/9a6d1fe3f00d86ab4ea6ea6ea0a5d48fc058a513",
        "digest": {
            "function_hash": "338751424987132939024747892497198054148",
            "length": 2455.0
        },
        "id": "CVE-2026-55204-0d78daeb",
        "deprecated": false,
        "target": {
            "file": "src/hpack-tbl.c",
            "function": "hpack_dht_insert"
        }
    },
    {
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/haproxy/haproxy/commit/9a6d1fe3f00d86ab4ea6ea6ea0a5d48fc058a513",
        "deprecated": false,
        "id": "CVE-2026-55204-4609dae9",
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
                "40908380705076211766954459725958104",
                "264508472132916529779782027168019563567",
                "7199169709347451960990779938033903923",
                "211161776252394108731142819930810131911"
            ]
        },
        "target": {
            "file": "src/hpack-tbl.c"
        }
    }
]