CVE-2021-25288 is a critical-severity (CVSS 9.1) Out-of-bounds Read vulnerability in pillow. A fix is available for pillow — see the affected versions and patch details below.
Pillow Out-of-bounds Read vulnerability
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-25288 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
pillowReal-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
An issue was discovered in Pillow before 8.2.0. There is an out-of-bounds read in J2kDecode, in j2ku_gray_i. This dates to Pillow 2.4.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pillow | ≥ 2.4.0&&< 8.2.0 | 8.2.0pip install --upgrade 'pillow==8.2.0' |
Affected Products
fedorafedoraprojectpillowpythonDetection & mitigation playbook
Open-source dependencyDetect
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 8.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-25288 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.
To mitigate this feature on Red Hat Quay keep the invoice generation feature disabled, as it is by default.Source: Red Hat security advisory for CVE-2021-25288 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 8 | python-pillow-0:5.1.1-16.el8 | RHSA-2021:4149 |
Frequently Asked Questions
Is CVE-2021-25288 in your dependencies?
Find it across PyPI, including transitive dependencies.