CVE-2026-51807

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-14 · updated 2026-07-17
Weakness: CWE-121

Description

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.

References

https://github.com/osamu620/OpenHTJ2K/blob/main/CHANGELOG
https://github.com/osamu620/OpenHTJ2K/commit/0778b93
https://github.com/osamu620/OpenHTJ2K/compare/0778b93...v0.18.4
https://github.com/osamu620/OpenHTJ2K/releases

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