CVE-2026-51807

Buffer Overflow vulnerability in OpenHTJ2K v.0.18.4 and before allows an attacker to execute...

9.8 Critical

Heap-based out-of-bounds write in j2k_precinct_subband::parse_packet_header() in OpenHTJ2K versions 0.18.3 and earlier (fixed in v0.18.4) caused by missing bounds validation before coding-pass lengths are written to j2k_codeblock::pass_length[128]. A crafted JPEG 2000 codestream containing malformed PPM packet headers can trigger a heap-based out-of-bounds write in j2k_precinct_subband::parse_packet_header() in source/core/coding/coding_units.cpp due to missing bounds validation for the j2k_codeblock::pass_length[128] array which can lead to heap corruption and process termination.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.67%Up 0.5 points since Jul 15, 2026

What each source reports

CVE List Score used 9.8

Record: CVE-2026-51807
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-121
Updated: 2026-11-02

EUVDEUVD-2026-44580 9.8

Record: EUVD-2026-44580
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-hr36-79f7-75x7 9.8

Buffer Overflow vulnerability in OpenHTJ2K v.0.18.4 and before allows an attacker to execute...

Buffer Overflow vulnerability in OpenHTJ2K v.0.18.4 and before allows an attacker to execute arbitrary code via the j2k_precinct_subband::parse_packet_header() in source/core/coding/coding_units.cpp

Record: GHSA-hr36-79f7-75x7
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-121
Updated: 2026-11-02

NVD 9.8

Record: CVE-2026-51807
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-121
Updated: 2026-11-02

OSV 9.8

Record: CVE-2026-51807
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-51807 is a critical vulnerability (CVSS 9.8), published July 14, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.67%, the 52nd percentile. No source names a fixed version.