Reference page — cumulative record through Saturday, October 3, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2020-6851

CVE-2020-6851HIGH

n/a n/a — OpenJPEG through 2.3.1 has a heap-based buffer overflow in opj_t1_clbl_decode_processor in openjp2/t1.c because of lack of opj_j2k_update…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  H    7.5   .0519   92.2     —

AFFECTED
  Product  Versions  Fixed
  n/a      n/a –     —

TIMELINE
  Jan 13  Reserved by mitre
  Jan 13  Published (CNA: mitre)
  Sep 22  ENRICHED — CVE-2020-6851. Received CVSS 7.5 and CPE data from NVD.
  Sep 22  EXPLOIT PUBLISHED — CVE-2020-6851. Public exploit reference added.

CWE-787 · CNA: mitre · CVSS v3.1 · 11 references · NVD status: Modified

Description

OpenJPEG through 2.3.1 has a heap-based buffer overflow in opj_t1_clbl_decode_processor in openjp2/t1.c because of lack of opj_j2k_update_image_dimensions validation.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
January 13, 2020	Reserved	Reserved by mitre
January 13, 2020	Published	Published (CNA: mitre)
September 22, 2026	ENRICHED	ENRICHED — CVE-2020-6851. Received CVSS 7.5 and CPE data from NVD.
September 22, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2020-6851. Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
n/a	n/a	—	n/a	—

Weaknesses

CWE-787

References (11)

http://www.openwall.com/lists/oss-security/2026/09/22/6
https://access.redhat.com/errata/RHSA-2020:0262 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2020:0274 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2020:0296 [Third Party Advisory]
https://github.com/uclouvain/openjpeg/issues/1228 [Exploit, Third Party Advisory]
https://lists.debian.org/debian-lts-announce/2020/01/msg00025.html [Mailing List, Third Party Advisory]
https://lists.debian.org/debian-lts-announce/2020/07/msg00008.html [Mailing List, Third Party Advisory]
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LACIIDDCKZJEPKTTFILSOSBQL7L3FC6V/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XBRMI2D3XPVWKE3V52KRBW7BJVLS5LD3/
https://www.debian.org/security/2021/dsa-4882 [Third Party Advisory]
https://www.oracle.com/security-alerts/cpujul2020.html [Patch, Third Party Advisory]

Authoritative record: CVE-2020-6851 at cve.org

Weaknesses: CWE-787

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2020-6851 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Saturday, October 3, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.