CVE-2026-51807

criticalCVSS 9.8covered by 1 sourcefirst seen 2026-07-14

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.

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Exploitation outlook

Low exploitation risk0.37% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 30% of all EPSS-scored CVEs.

Advisory coverage (1)

criticalCVE-2026-51807: Heap-based out-of-bounds write in j2k_precinct_subband::parse_packet_header() in OpenHTJ2K ver…nvd · 2026-07-14

External references

NVD record for CVE-2026-51807

CVE.org record

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