Buffer overflow in N/a

CVE-2026-51807

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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.007 (51.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-51807: held from 0.007 to 0.007.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-51807?
CVE-2026-51807 is a critical-severity vulnerability in N/a, classified under Stack-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-07-14.
How severe is CVE-2026-51807?
Critical severity. CVSS v3 base score is 9.8 out of 10.