CVE-2021-25287 [Critical] | Out-of-bounds Read in Pillow

CVE-2021-25287 is rated High Risk (66.1/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 2.88%). High exploitation likelihood—assess exposure and prioritize remediation.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-23	2.96%	2.88%	-0.08%
2	2026-06-15	0.34%	2.96%	+2.61%
3	2026-04-25	—	0.34%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-23

2.96%

2.88%

-0.08%

2026-06-15

0.34%

2.96%

+2.61%

2026-04-25

—

0.34%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
9.1	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.2	[email protected]
6.4	2.0	MEDIUM	`AV:N/AC:L/Au:N/C:P/I:N/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:P) Partial availability impact.	10.0	4.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

9.1

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.2

[email protected]

6.4

2.0

MEDIUM

AV:N/AC:L/Au:N/C:P/I:N/A:P Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

4.9

[email protected]

OS Trackers for CVE-2021-25287

vendor	priority	summary	link
`alpine`	critical	CVE-2021-25287: 1 source package rows (py3-pillow); 8 state rows across 8 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community, edge-main); fixed 8, open 0.	https://security.alpinelinux.org/vuln/CVE-2021-25287
`debian`	unimportant	CVE-2021-25287 unimportant priority: Debian including 1 source packages (pillow), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2021-25287
`gentoo`	normal	CVE-2021-25287: 1 GLSA(s) (202107-33), 1 atom(s) (dev-python/pillow); latest impact normal.	https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-25287
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2021-25287
`suse`	high	CVE-2021-25287 severity important: SUSE including 9 source package names (python-Pillow, python-Pillow-2.8.1-4.22.1, …), 33 product×package rows across 17 product lines (HPE Helion OpenStack 8, SUSE Liberty Linux 8, … (17 product lines)): Known Not Affected 21, Fixed 12.	https://www.suse.com/security/cve/CVE-2021-25287/
`ubuntu`	low	CVE-2021-25287 low priority: Ubuntu including 3 source packages (pillow, pillow-python2, python-imaging), 48 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 28, released 15, ignored 2, needs-triage 2, not-affected 1.	https://ubuntu.com/security/CVE-2021-25287

Affected software / configurations for CVE-2021-25287

Vendor	Product	Version	Raw CPE
python	pillow	< 8.2.0	cpe:2.3:a:python:pillow::::::::
fedoraproject	fedora	33	cpe:2.3:o:fedoraproject:fedora:33:::::::*

References for CVE-2021-25287

URL	Tags
https://github.com/python-pillow/Pillow/pull/5377#issuecomment-833821470	Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MQHA5HAIBOYI3R6HDWCLAGFTIQP767FL/
https://pillow.readthedocs.io/en/stable/releasenotes/8.2.0.html#cve-2021-25287-cve-2021-25288-fix-oob-read-in-jpeg2kdecode	Vendor Advisory
https://security.gentoo.org/glsa/202107-33	Third Party Advisory

URL

CVE-2021-25287

Exploit prediction scoring system (EPSS) score for CVE-2021-25287

Common vulnerability scoring system (CVSS) metrics for CVE-2021-25287

Weakness enumeration for CVE-2021-25287

GitHub Security Advisory for CVE-2021-25287

OS Trackers for CVE-2021-25287

Affected software / configurations for CVE-2021-25287

References for CVE-2021-25287