python-pillow Pillow Heap-Based Buffer Overflow Flaw (CVE-2026-112398) Rated CVSS 9.2
A newly published critical vulnerability in python-pillow Pillow carries a CVSS score of 9.2. Here is what is affected and how to respond.
Key points
- CVE-2026-112398 affects python-pillow Pillow.
- CVSS 9.2 (Critical).
- No exploitation confirmed yet.
python-pillow Pillow is affected by CVE-2026-112398, a heap-based buffer overflow that the National Vulnerability Database rates 9.2 out of 10.
At a glance
- CVE
- CVE-2026-112398
- Product
- python-pillow Pillow
- CVSS
- 9.2 Critical
- Weakness
- heap-based buffer overflow
- Exploited
- No known exploitation
What is the vulnerability?
The NVD entry states: Pillow is a Python imaging library. Prior to 13.0.0, Pillow's FlashPix JPEG-tile decoder can write decoded scanlines beyond the allocated tile buffer. FlashPix (FPX) JPEG decoding selects raw mode LA with two bytes per pixel, while an unrecognized JPEG mode can be decoded as JCS_UNKNOWN with four components, causing ImagingJpegDecode to write four-component scanlines into the two-byte tile buffer. An attacker can supply a crafted OLE2 FlashPix file to an application with the optional olefile dependency installed that opens or thumbnails untrusted input. This can corrupt heap memory and may allow arbitrary code execution. This issue is fixed in version 13.0.0.
Affected versions
| Vendor | Product | Versions |
|---|---|---|
| Python-Pillow | Pillow | < 13.0.0 |
Is it being exploited?
There is no public confirmation of exploitation at the time of publication. It does not appear in CISA's Known Exploited Vulnerabilities catalog. We will update this report if that changes.
What should you do?
- Identify whether the affected product and versions run in your environment.
- Apply the vendor update listed in the advisory as soon as it is available.
- Limit network exposure of the affected service until it is patched.
- Monitor the vendor advisory for updated guidance or exploitation reports.
What to do and how to stay safe: CVE-2026-112398
- Vulnerability severity scores ignore your specific architecture and context.
- Exploitability depends on network exposure and user behavior, not just code flaws.
- Prioritization requires continuous asset inventory and threat intelligence alignment.
Risk-based vulnerability management focuses your limited resources on the flaws that actually threaten your business. Start by mapping your critical assets and checking for active exploits to prioritize your backlog.
Step-by-step guide: Risk-Based Vulnerability Management: Prioritize Fixes by Actual Danger
General security guidance from the Threat Times newsroom. It is not confirmed advice from the organisations named in this story.
Frequently asked questions
What is CVE-2026-112398?
CVE-2026-112398 is a heap-based buffer overflow vulnerability in python-pillow Pillow.
How severe is CVE-2026-112398?
It has a CVSS score of 9.2 Critical.
Is CVE-2026-112398 being exploited?
There is no public confirmation of exploitation at the time of publication.
