vulnerability / NVI-00010701 / Revision 2
Pillow: Heap buffer overflow in _tiffWriteProc when saving TIFF to BytesIO
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.
1.019%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.63401. 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>= 2.0.0, < 13.0.0
``` ============================================================================ Heap buffer overflow in _tiffWriteProc when saving TIFF to BytesIO Location: src/libImaging/TiffDecode.c:94 in _tiffWriteProc() Commit: a707c6b21c313880d0771e54965d142dd42358b6 ============================================================================ ``` Pillow can write attacker-chosen data past the end of a heap buffer when it saves a TIFF image to an in-memory destination such as `io.BytesIO` rather than to a file. The same code also copies leftover heap memory from the process into the saved file. Anyone who can supply an image to a service that opens it and re-saves it as TIFF this way can trigger this with default settings. The attached reproducer crashes the process, and the overflow could potentially be developed further, but code execution is not demonstrated here. The bug is in `_tiffWriteProc` in `src/libImaging/TiffDecode.c`. This is the write callback for the in-memory sink that Pillow gives libtiff whenever the save target has no `fileno()`. While writing the directory, libtiff seeks past the current end of data and writes tag values there. `_tiffWriteProc` sizes its `realloc()` f
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-332p-7hrc-92wf ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-112393 ↗
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 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.