vulnerability / NVI-00010725 / Revision 4
Pillow: NULL pointer dereference in Image.merge via an unvalidated band 0
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.
7.5 HIGH (3.1)
nvd@nist.gov severity; no combined Null risk score.
8.7 HIGH (4.0)
security-advisories@github.com severity; no combined Null risk score.
0.594%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.48426. 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>= 12.0.0, < 13.0.0
### Summary `Image.merge()` checks the mode of every input band except band 0. If band 0 is a single-band `I` or `F` image, the native merge routine reads a pixel pointer that is NULL for those modes and the process crashes. The IPTC plugin reaches this from a plain `Image.open()` followed by a load, and IPTC has no magic-byte prefilter, so a crafted file with no recognizable header can drive it. ### Details The validation loop skips band 0: - `src/PIL/Image.py:3795` iterates `for band in bands[1:]` and checks mode and size only for those. For an `I` or `F` image the 8-bit plane `image8` is NULL (only `image32` is set). `ImagingMerge` dereferences `bands[0]->image8[y]` for the multi-band output modes: - `src/libImaging/Bands.c:302`, `:311`, `:321` The IPTC loader builds the band list from an attacker-typed sub-image and passes it to merge with the sub-image at index 0: - `src/PIL/IptcImagePlugin.py:156-160` - `src/PIL/IptcImagePlugin.py:169` registers the opener with no accept function. ### PoC ```python from PIL import Image # Band 0 is a single-band "I" image: its image8 plane is NULL. merge() validates only # bands[1:], so the native ImagingMerge dereferences the NULL pl
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.
- NVD lastModified does not establish freshness of every associated CPE record.
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-cp9v-662q-vvx9 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-112405 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
- CVE-2026-112405 ↗
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 4 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 3 ·
Source facts changed; compare the preserved prior revision.
- 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.