CVE-2021-25292

An issue was discovered in Pillow before 8.1.1. The PDF parser allows a regular expression DoS (ReDoS) attack via a crafted PDF file because of a catastrophic backtracking regex.

Published: 2021-03-19 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-25292 is rated Moderate Risk (53/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.64%). EPSS rose +1.45% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-25292

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.18% 1.64% +1.45%
2 2026-04-21 0.15% 0.18% +0.04%
3 2025-12-24 — 0.15% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-25292

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful 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.
 2.8 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2021-25292

GitHub Security Advisory for CVE-2021-25292

GHSA-9hx2-hgq2-2g4f · Severity: medium · Ecosystem: pip — Regular Expression Denial of Service (ReDoS) in Pillow

OS Trackers for CVE-2021-25292

vendor priority summary link
alpine medium CVE-2021-25292: 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-2021-25292
debian not yet assigned CVE-2021-25292 not yet assigned 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-2021-25292
gentoo normal CVE-2021-25292: 1 GLSA(s) (202107-33), 1 atom(s) (dev-python/pillow); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-25292
redhat medium — https://access.redhat.com/security/cve/CVE-2021-25292
suse high CVE-2021-25292 severity important: SUSE including 27 source package names (python-Pillow, python-Pillow-4.2.1-3.14.1, …), 55 product×package rows across 20 product lines (HPE Helion OpenStack 8, SUSE Liberty Linux 8, … (20 product lines)): Fixed 31, Known Not Affected 24. https://www.suse.com/security/cve/CVE-2021-25292/
ubuntu medium CVE-2021-25292 medium 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, not-affected 12, released 4, needs-triage 3, ignored 1. https://ubuntu.com/security/CVE-2021-25292

Affected software / configurations for CVE-2021-25292

Vendor Product Version Raw CPE
python pillow < 8.1.1 cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:*

References for CVE-2021-25292

cvelogic Threat Intelligence