CVE-2026-51808
Buffer overflow RCE in OpenHTJ2K decoder when parsing crafted JPEG2000 data
Is CVE-2026-51808 being exploited?
Not confirmed. CVE-2026-51808 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.85% probability of exploitation in the next 30 days.
How severe is CVE-2026-51808?
CVE-2026-51808 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-51808?
Yes. A fix has been recorded for CVE-2026-51808. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-51808 affect?
CVE-2026-51808 affects OpenHTJ2K <= 0.18.4, Any application using OpenHTJ2K decoder for JPEG2000 processing. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-51808?
Upgrade to vendor-patched OpenHTJ2K when available; block/scan untrusted JPEG2000 files.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution via buffer overflow in decoder functions (invoke*), allowing execution of arbitrary code from crafted JPEG2000 inputs.
Immediate action required