vulnerability / NVI-00010595 / Revision 3
Pillow: ReDoS in XbmImagePlugin: 512-byte file stalls Image.open() for minutes
GitHub lists this reviewed advisory for Pillow. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
0.532%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.4499. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
Pillow
source listed<= 12.3.0
``` ============================================================================ ReDoS in XbmImagePlugin: 512-byte file stalls Image.open() for minutes Location: src/PIL/XbmImagePlugin.py:58 in XbmImageFile._open() Commit: a707c6b21c313880d0771e54965d142dd42358b6 ============================================================================ ``` A crafted 512-byte file makes Pillow's `Image.open()` spend about six minutes of processor time on one core before it gives up with `UnidentifiedImageError`. Anyone who can hand bytes to an application that opens images with Pillow's default settings can trigger this, for example through an upload form, a thumbnailer, or a service that checks whether a blob is an image. A few such files sent at once can tie up a typical pool of worker processes. The cause is the `xbm_head` regular expression in `src/PIL/XbmImagePlugin.py:32-40`, which `XbmImageFile._open()` (line 58) runs over the first 512 bytes of any stream whose prefix starts with `#define`. Several adjacent parts of the pattern can match the same characters. `[ \t]+` overlaps with `.*` in the width and height lines and with `[^_]*` in the optional hotspot lines, and `[\r\n]+` closing
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-xgh8-jp6q-p5x8 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-112901 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 3 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 2 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.