PillowApplication · Python
CVE-2026-59203
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedPillow is a Python imaging library. From 12.0.0 through 12.2.0, Pillow's EPS parser in PIL/EpsImagePlugin.py accepts a negative byte count in the %%BeginBinary directive, allowing a crafted EPS file to cause Image.open() to seek backwards to the same directive and parse it repeatedly in an infinite loop. This issue is fixed in version 12.3.0.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidencePillow's EPS image parser in PIL/EpsImagePlugin.py accepts a negative byte count in the %%BeginBinary directive, allowing a crafted EPS file to cause Image.open() to seek backwards to the same directive and parse it repeatedly in an infinite loop, resulting in denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
PillowApplication
>= 12.0.0, < 12.3.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Check installed Pillow versionRun `python -c "import PIL; print(PIL.__version__)"` or `pip show pillow` to see the installed versionAffected if Version is 12.0.0 or higher but lower than 12.3.0
-
Confirm EpsImagePlugin is availableRun `python -c "from PIL import EpsImagePlugin; print('Available')"` to verify the EPS parser module existsAffected if The module loads without error, meaning the vulnerable EPS parsing code is present
-
Identify if your application processes EPS filesSearch your codebase for calls to `Image.open()` with .eps file extensions, or check if EPS is an enabled format in your image processing pipelineAffected if Your application or system uses Pillow to open or process EPS image files
-
Check EpsImagePlugin source for vulnerable directive handlingLocate PIL/EpsImagePlugin.py in your environment and search for "BeginBinary" to see how the %%BeginBinary directive is handledAffected if The code processes the %%BeginBinary directive and uses the byte count without validating it is non-negative
You are affected if you have Pillow version 12.0.0 through 12.2.x installed AND your environment uses Pillow to process EPS image files.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped12.3.0
Upgrade Pillow to version 12.3.0 or later to patch the vulnerable EPS parser; if upgrading is not immediately feasible, avoid opening untrusted EPS files from unknown sources.
Pillow 12.3.0
- Upgrade Pillow to version 12.3.0 or later using pip: pip install 'Pillow>=12.3.0'
- Verify the upgrade was successful by running: pip show Pillow
- Ensure your application code that uses Image.open() to process EPS files no longer enters an infinite loop with crafted files
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Pillow
Scoped from the published advisory
- Consultation1.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,376.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-59203 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-59203 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data