Leptonica before 1.80.0 allows a denial of service (application crash) via an incorrect left shift in pixConvert2To8 in pixconv.c.

published 2021-03-11 5 y ago modified 2026-07-18 3 mo ago also EUVD-2020-23820 , JLSEC-2026-205

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 2.4%; EPSS 2.4% chance of exploitation in 30 days, percentile 84%
public exploits: 0; none known

Patch / fix

fixed in 2 distros 1 links 2

julia Leptonica_jll 1.81.1+0
leptonica leptonica 1.80.0

leptonlib Debian 14, Debian 13, Debian 12 1.79.0-1.1

debian advisories DEBIAN-CVE-2020-36277

github.com/DanBloomberg/leptonica#499 pull request
github.com/DanBloomberg/leptonica/compare/1.79.0...1.80.0 advisory

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-2020-36277 updated 2026-06-26 cvss 7.5

leptonica: DoS via an incorrect left shift in pixConvert2To8 in pixconv.c

Red Hat All currently supported Red Hat products
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

2.43% chance of exploitation in the next 30 days, higher than 84% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

bugs.chromium.org https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=21997 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	Leptonica_jll	<1.81.1+0	1.81.1+0

Classification

Weakness

CWE-670 Always-Incorrect Control Flow Implementation

References

github.com /DanBloomberg/leptonica/pull/499
patch, third-party-advisory, web
github.com /DanBloomberg/leptonica/compare/1.79.0...1.80.0
patch, release-notes, third-party-advisory, web
bugs.chromium.org /p/oss-fuzz/issues/detail?id=21997
exploit, issue-tracking, third-party-advisory, web
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/RD5AIWHWE334HGYZJR2U3I3JYKSSO2LW/
vendor-advisory, web
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/JQUEA2X6UTH4DMYCMZAWE2QQLN5YANUA/
vendor-advisory, web
security.gentoo.org /glsa/202107-53
vendor-advisory, third-party-advisory, web
lists.debian.org /debian-lts-announce/2021/03/msg00037.html
mailing-list, third-party-advisory, web

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.

Summary