CVE-2021-28677

An issue was discovered in Pillow before 8.2.0. For EPS data, the readline implementation used in EPSImageFile has to deal with any combination of \r and \n as line endings. It used an accidentally quadratic method of accumulating lines while looking for a line ending. A malicious EPS file could use this to perform a DoS of Pillow in the open phase, before an image was accepted for opening.

Published: 2021-06-02 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-28677 is rated Moderate Risk (58.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.29%). Mandatory action: 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-2021-28677

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 2026-06-23 2.36% 2.29% -0.06%
2 2026-06-15 0.26% 2.36% +2.09%
3 2025-11-21 0.26%

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-28677

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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: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: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.
3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/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:L)
Exploitation conditions are straightforward and predictable.
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.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-28677

GitHub Security Advisory for CVE-2021-28677

GHSA-q5hq-fp76-qmrc · Severity: high · Ecosystem: pip — Uncontrolled Resource Consumption in Pillow

OS Trackers for CVE-2021-28677

vendor priority summary link
alpine high CVE-2021-28677: 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-2021-28677
debian not yet assigned CVE-2021-28677 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-2021-28677
gentoo normal CVE-2021-28677: 1 GLSA(s) (202107-33), 1 atom(s) (dev-python/pillow); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-28677
redhat medium https://access.redhat.com/security/cve/CVE-2021-28677
suse high CVE-2021-28677 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-2021-28677/
ubuntu low CVE-2021-28677 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 16, ignored 2, needs-triage 2. https://ubuntu.com/security/CVE-2021-28677

Affected software / configurations for CVE-2021-28677

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-2021-28677

cvelogic Threat Intelligence