How severe is CVE-2020-5311?

CVE-2020-5311 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-5311?

CVE-2020-5311 affects the following packages: pillow (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2020-5311?

Update pillow to 6.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-5311 is resolved across your whole dependency graph.

How do I detect CVE-2020-5311 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pillow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2020-5311 if there is no patch (or I can't update yet)?

Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

Is CVE-2020-5311 actively exploited in the wild?

No public exploit code has been indexed for CVE-2020-5311 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2020-5311?

CVE-2020-5311 has an EPSS (Exploit Prediction Scoring System) score of 4.0%, placing it in the 91th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2020-5311?

CVE-2020-5311 is classified as CWE-120 (CWE-120). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2020-5311 published, and has it been updated?

CVE-2020-5311 was published on January 3, 2020 and was last updated on October 24, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

CRITICAL severity

CVE-2020-5311 — pillow

CRITICALFix: python-pillow/Pillow@a79b65c

CVE-2020-5311 is a critical-severity (CVSS 9.8) CWE-120 vulnerability in pillow. A fix is available for pillow — see the affected versions and patch details below.

Buffer Copy without Checking Size of Input in Pillow

Also known asBIT-pillow-2020-5311GHSA-r7rm-8j6h-r933PYSEC-2020-82

Published

Jan 3, 2020

Updated

Oct 24, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

4.0%probability of exploitation in next 30 days

Lower Risk-0.16%

Lower risk than most CVEs91th percentile — riskier than 91% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐍pillow

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

libImaging/SgiRleDecode.c in Pillow before 6.2.2 has an SGI buffer overflow.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`pillow`	all versions	6.2.2`pip install --upgrade 'pillow==6.2.2'`

Affected Products

4 products · 7 configurations

ubuntu linuxcanonical

2 versions

18.0419.10

debian linuxdebian

2 versions

9.010.0

fedorafedoraproject

2 versions

3031

Application

pillowpython

< 6.2.2

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pillow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pillow to 6.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-5311 is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

This issue did not affect the versions of python-pillow and python-imaging as shipped with Red Hat Enterprise Linux 6, and 7 as they did not include the SGI RLE image decoder, where the flaw lies.

Product	Fixed in	Advisory
Red Hat Enterprise Linux 8	`python-pillow-0:5.1.1-10.el8_1`	RHSA-2020:0580
Red Hat Enterprise Linux 8.0 Update Services for SAP Solutions	`python-pillow-0:5.1.1-10.el8_0`	RHSA-2020:0566
Red Hat Quay 3	`quay/clair-rhel8:v3.4.0-25`	RHSA-2021:0420

Frequently Asked Questions

libImaging/SgiRleDecode.c in Pillow before 6.2.2 has an SGI buffer overflow.

O3 Security · Impact-Aware SCA

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CVE-2020-5311 — pillow

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2020-5311 in your dependencies?