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Fencer Vulns
high 7.5

CVE-2020-6851 json

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_i…

published 2020-01-13 6 y ago modified 2026-09-22 47 d ago also EUVD-2020-27994 , JLSEC-2026-543

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.3%
EPSS 5.3% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

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.

Patch / fix

  • julia OpenJpeg_jll 2.4.0+0
  • openjpeg2 Debian 14, Debian 13, Debian 12 2.4.0-1

debian advisories DEBIAN-CVE-2020-6851

  • openjpeg2 Ubuntu 16.04 LTS 2.1.2-1.1+deb9u5build0.16.04.1
  • openjpeg2 Ubuntu 18.04 LTS 2.3.0-2+deb10u2build0.18.04.1
  • openjpeg2 Ubuntu 20.04 LTS 2.3.1-1ubuntu4
  • ghostscript Ubuntu 16.04 LTS 9.26~dfsg+0-0ubuntu0.16.04.14
  • ghostscript Ubuntu 18.04 LTS 9.26~dfsg+0-0ubuntu0.18.04.14

ubuntu advisories UBUNTU-CVE-2020-6851

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • openjpeg2 RHEL 8 2.3.1-2.el8_1
  • openjpeg2-tools RHEL 8 2.3.1-2.el8_1
  • openjpeg2 RHEL 7 2.3.1-2.el7_7
  • openjpeg2-tools RHEL 7 2.3.1-2.el7_7
  • openjpeg2 RHEL 8.0 E4S 2.3.0-9.el8_0
  • openjpeg2-tools RHEL 8.0 E4S 2.3.0-9.el8_0

red hat advisories RHSA-2020:0296RHSA-2020:0274RHSA-2020:0262

  • libheif SLES for SAP applications 16.0, SLES 16.0 1.23.5-160000.1.1
  • libheif SLE Module for Package Hub 15 SP7, SLE Module for Desktop Applications 15 SP7 1.23.5-150700.3.24.1
  • openjpeg2 SLES for SAP 15 SP2, SLES for SAP 15 SP1, SLES for SAP 15 +20 more 2.3.0-150000.3.5.1

suse advisories SUSE-SU-2026:24205-1SUSE-SU-2026:4378-1SUSE-SU-2022:1252-1

  • libheif openSUSE Leap 16.0 1.23.5-160000.1.1
  • libheif openSUSE Tumbleweed 1.23.5-1.1

opensuse advisories openSUSE-SU-2026:22052-1openSUSE-SU-2026:11859-1

  • openjpeg Alpine 3.24, Alpine 3.23, Alpine 3.22 +12 more 2.3.1-r3
  • openjpeg Alpine 3.8 2.3.0-r4
  • openjpeg Alpine 3.9 2.3.0-r5

alpine advisories ALPINE-CVE-2020-6851

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • openjpeg2 Arch Linux 2.4.0-1

arch linux advisories AVG-1339

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-6851 updated cvss 8.1

openjpeg: Heap-based buffer overflow in opj_t1_clbl_decode_processor()

  • Red Hat CodeReady Linux Builder (v. 8) openjpeg2-tools 2.3.1-2.el8_1 Red Hat Enterprise Linux AppStream (v. 8) openjpeg2 2.3.1-2.el8_1, openjpeg2-tools 2.3.1-2.el8_1
    fixed: vendor fix RHSA-2020:0274
  • Red Hat Enterprise Linux AppStream E4S (v. 8.0) openjpeg2 2.3.0-9.el8_0, openjpeg2-tools 2.3.0-9.el8_0
    fixed: vendor fix RHSA-2020:0296
  • Red Hat Enterprise Linux Client (v. 7) openjpeg2 2.3.1-2.el7_7 Red Hat Enterprise Linux Client Optional (v. 7) openjpeg2-tools 2.3.1-2.el7_7 Red Hat Enterprise Linux ComputeNode (v. 7) openjpeg2 2.3.1-2.el7_7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) openjpeg2-tools 2.3.1-2.el7_7 Red Hat Enterprise Linux Server (v. 7) openjpeg2 2.3.1-2.el7_7 Red Hat Enterprise Linux Server Optional (v. 7) openjpeg2-tools 2.3.1-2.el7_7
    +2 more products
    Red Hat Enterprise Linux Workstation (v. 7) openjpeg2 2.3.1-2.el7_7 Red Hat Enterprise Linux Workstation Optional (v. 7) openjpeg2-tools 2.3.1-2.el7_7
    fixed: vendor fix RHSA-2020:0262
  • Red Hat Enterprise Linux 6 openjpeg, openjpeg-libs Red Hat Enterprise Linux 7 openjpeg, openjpeg-libs
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

5.29% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/uclouvain/openjpeg/issues/1228 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
julia OpenJpeg_jll
<2.4.0+0
2.4.0+0

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.