CVE catalog

CVE-2021-23437

pillow: CVE-2021-23437

Severity: High · CVSS 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: Sep 3, 2021, 12:00:00 AM UTC
Source: [NVD] · [CVE record]
EPSS: 3.24% · Oct 25, 2026

The package pillow 5.2.0 and before 8.3.2 are vulnerable to Regular Expression Denial of Service (ReDoS) via the getrgb function.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	pillow	sid	`13.0.0-1`	fixed
Debian	pillow	forky	`12.3.0-1`	fixed
Debian	pillow	trixie	`11.1.0-5+deb13u4`	fixed
Debian	pillow	trixie-security	`11.1.0-5+deb13u3`	fixed
Debian	pillow	bookworm	`9.4.0-1.1+deb12u1`	fixed
Debian	pillow	bookworm-security	`9.4.0-1.1+deb12u1`	fixed
Alpine	py-pillow	3.11	`6.2.1-r1`	fixed
Alpine	py3-pillow	3.12	`7.1.2-r2`	fixed
Alpine	py3-pillow	3.13	`7.2.0-r2`	fixed
Alpine	py3-pillow	3.14	`8.2.0-r1`	fixed
Alpine	py3-pillow	3.15	`8.4.0-r0`	fixed
Ubuntu	pillow	pro	`2.9.0-1`	vulnerable
Ubuntu	pillow	pro	`3.0.0-1`	vulnerable
Ubuntu	pillow	pro	`3.0.0-1build1`	vulnerable
Ubuntu	pillow	pro	`3.1.0-1`	vulnerable
Ubuntu	pillow	pro	`3.1.1-1`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1.1`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1.3`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1.4`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1.5`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1.6`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1.6+esm1`	fixed
Ubuntu	pillow	18.04	`4.1.1-3build2`	vulnerable
Ubuntu	pillow	18.04	`4.3.0-2ubuntu1`	vulnerable
Ubuntu	pillow	18.04	`5.0.0-1`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1ubuntu0.2`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1ubuntu0.3`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1ubuntu0.4`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1ubuntu0.5`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1ubuntu0.6`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1ubuntu0.7`	fixed
Ubuntu	pillow	20.04	`6.1.0-1`	vulnerable
Ubuntu	pillow	20.04	`6.1.0-1build1`	vulnerable
Ubuntu	pillow	20.04	`6.2.1-2`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4build1`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4ubuntu0.1`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4ubuntu0.2`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4ubuntu0.3`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4ubuntu0.4`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4ubuntu0.5`	fixed
Suse	python-Pillow	openstack cloud 9	`5.2.0-3.14.1`	fixed
Suse	python-Pillow	openstack cloud crowbar 9	`5.2.0-3.14.1`	fixed
Ubuntu	pillow	pro	`2.9.0-1`	vulnerable
Ubuntu	pillow	pro	`3.0.0-1`	vulnerable
Ubuntu	pillow	pro	`3.0.0-1build1`	vulnerable
Ubuntu	pillow	pro	`3.1.0-1`	vulnerable
Ubuntu	pillow	pro	`3.1.1-1`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1.1`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1.3`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1.4`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1.5`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1.6`	vulnerable
Ubuntu	pillow	pro	`3.1.2-0ubuntu1.6+esm1`	fixed
Ubuntu	pillow	18.04	`4.1.1-3build2`	vulnerable
Ubuntu	pillow	18.04	`4.3.0-2ubuntu1`	vulnerable
Ubuntu	pillow	18.04	`5.0.0-1`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1ubuntu0.2`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1ubuntu0.3`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1ubuntu0.4`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1ubuntu0.5`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1ubuntu0.6`	vulnerable
Ubuntu	pillow	18.04	`5.1.0-1ubuntu0.7`	fixed
Ubuntu	pillow	20.04	`6.1.0-1`	vulnerable
Ubuntu	pillow	20.04	`6.1.0-1build1`	vulnerable
Ubuntu	pillow	20.04	`6.2.1-2`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4build1`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4ubuntu0.1`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4ubuntu0.2`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4ubuntu0.3`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4ubuntu0.4`	vulnerable
Ubuntu	pillow	20.04	`7.0.0-4ubuntu0.5`	fixed
Ubuntu	pillow-python2	pro	`6.2.1-3~build1`	vulnerable
Ubuntu	pillow-python2	pro	`6.2.1-3`	vulnerable
Ubuntu	pillow-python2	pro	`6.2.1-3ubuntu0.1~esm1`	vulnerable
Ubuntu	pillow-python2	pro	`6.2.1-3ubuntu0.1~esm2`	vulnerable
Ubuntu	pillow	22.04	`8.1.2+dfsg-0.3`	vulnerable
Ubuntu	pillow	22.04	`9.0.0-1`	fixed
Suse	python-Pillow	hpe helion openstack 8	`4.2.1-3.20.2`	fixed
Suse	python-Pillow	openstack cloud 8	`4.2.1-3.20.2`	fixed
Suse	python-Pillow	openstack cloud crowbar 8	`4.2.1-3.20.2`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	pillow	source	sid	`8.3.2-1`	not yet assigned	Not reported	Not reported
Debian	pillow	source	forky	`8.3.2-1`	not yet assigned	Not reported	Not reported
Debian	pillow	source	trixie	`8.3.2-1`	not yet assigned	Not reported	Not reported
Debian	pillow	source	bookworm	`8.3.2-1`	not yet assigned	Not reported	Not reported
Alpine	py-pillow	apk	3.11	`6.2.1-r1`	Not reported	ALPINE-CVE-2021-23437	Not reported
Alpine	py3-pillow	apk	3.12	`7.1.2-r2`	Not reported	ALPINE-CVE-2021-23437	Not reported
Alpine	py3-pillow	apk	3.13	`7.2.0-r2`	Not reported	ALPINE-CVE-2021-23437	Not reported
Alpine	py3-pillow	apk	3.14	`8.2.0-r1`	Not reported	ALPINE-CVE-2021-23437	Not reported
Alpine	py3-pillow	apk	3.15	`8.4.0-r0`	Not reported	ALPINE-CVE-2021-23437	Not reported
Ubuntu	pillow	deb	pro	`3.1.2-0ubuntu1.6+esm1`	Not reported	USN-5227-2	Not reported
Ubuntu	pillow	deb	18.04	`5.1.0-1ubuntu0.7`	Not reported	USN-5227-1	Not reported
Ubuntu	pillow	deb	20.04	`7.0.0-4ubuntu0.5`	Not reported	USN-5227-1	Not reported
Suse	python-Pillow	rpm	openstack cloud 9	`5.2.0-3.14.1`	Not reported	SUSE-SU-2021:3235-1	Not reported
Suse	python-Pillow	rpm	openstack cloud crowbar 9	`5.2.0-3.14.1`	Not reported	SUSE-SU-2021:3235-1	Not reported
Ubuntu	pillow	deb	pro	`3.1.2-0ubuntu1.6+esm1`	Not reported	UBUNTU-CVE-2021-23437	Not reported
Ubuntu	pillow	deb	18.04	`5.1.0-1ubuntu0.7`	Not reported	UBUNTU-CVE-2021-23437	Not reported
Ubuntu	pillow	deb	20.04	`7.0.0-4ubuntu0.5`	Not reported	UBUNTU-CVE-2021-23437	Not reported
Ubuntu	pillow	deb	22.04	`9.0.0-1`	Not reported	UBUNTU-CVE-2021-23437	Not reported
Suse	python-Pillow	rpm	hpe helion openstack 8	`4.2.1-3.20.2`	Not reported	SUSE-SU-2021:3234-1	Not reported
Suse	python-Pillow	rpm	openstack cloud 8	`4.2.1-3.20.2`	Not reported	SUSE-SU-2021:3234-1	Not reported
Suse	python-Pillow	rpm	openstack cloud crowbar 8	`4.2.1-3.20.2`	Not reported	SUSE-SU-2021:3234-1	Not reported

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

[python3-pil]Unknown
Source package: [pillow]
Details (4)
- 9.4.0-1.1+deb12u1 · amd64 · bookworm
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · bookworm; dsa · pillow · debian · 12
- 9.4.0-1.1+deb12u1 · arm64 · bookworm
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · bookworm; dsa · pillow · debian · 12
- 9.4.0-1.1+deb12u1 · amd64 · bookworm-security
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · bookworm; dsa · pillow · debian · 12
- 9.4.0-1.1+deb12u1 · arm64 · bookworm-security
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · bookworm; dsa · pillow · debian · 12
[python3-pil.imagetk]Unknown
Source package: [pillow]
Details (4)
- 9.4.0-1.1+deb12u1 · amd64 · bookworm
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · bookworm; dsa · pillow · debian · 12
- 9.4.0-1.1+deb12u1 · arm64 · bookworm
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · bookworm; dsa · pillow · debian · 12
- 9.4.0-1.1+deb12u1 · amd64 · bookworm-security
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · bookworm; dsa · pillow · debian · 12
- 9.4.0-1.1+deb12u1 · arm64 · bookworm-security
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · bookworm; dsa · pillow · debian · 12
[python-pil-doc]Unknown
Source package: [pillow]
Details (4)
- 9.4.0-1.1+deb12u1 · all · bookworm
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · bookworm; dsa · pillow · debian · 12
- 9.4.0-1.1+deb12u1 · all · bookworm
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · bookworm; dsa · pillow · debian · 12
- 9.4.0-1.1+deb12u1 · all · bookworm-security
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · bookworm; dsa · pillow · debian · 12
- 9.4.0-1.1+deb12u1 · all · bookworm-security
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · bookworm; dsa · pillow · debian · 12

[Debian 13 (Trixie)]

[python3-pil]Unknown
Source package: [pillow]
Details (4)
- 11.1.0-5+deb13u4 · amd64 · trixie
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · 13
- 11.1.0-5+deb13u4 · arm64 · trixie
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · 13
- 11.1.0-5+deb13u3 · amd64 · trixie-security
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · 13
- 11.1.0-5+deb13u3 · arm64 · trixie-security
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · 13
[python3-pil.imagetk]Unknown
Source package: [pillow]
Details (4)
- 11.1.0-5+deb13u4 · amd64 · trixie
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · 13
- 11.1.0-5+deb13u4 · arm64 · trixie
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · 13
- 11.1.0-5+deb13u3 · amd64 · trixie-security
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · 13
- 11.1.0-5+deb13u3 · arm64 · trixie-security
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · 13
[python-pil-doc]Unknown
Source package: [pillow]
Details (4)
- 11.1.0-5+deb13u4 · all · trixie
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · 13
- 11.1.0-5+deb13u4 · all · trixie
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · 13
- 11.1.0-5+deb13u3 · all · trixie-security
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · 13
- 11.1.0-5+deb13u3 · all · trixie-security
  Fixed · Fixed: 8.3.2-1
  dsa · pillow · debian · 13

Observed: Oct 23, 2026, 5:54:54 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]