CVE-2026-112397: Pillow · Out-of-bounds access in _imagingmorph on a zero-width image
Affects aiderSource GCVE Database
Not known to be exploited · CVSS 8.7 High.
Data as of 30 Oct 2026, 07:30 UTC
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 19 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewaiderpkg:brew/aiderOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### Summary A PPM or PGM file can declare a width of 0, which Pillow accepts, producing an image of size `(0, N)`. Passing that image to `ImageMorph.MorphOp.apply()` makes the native morphology code index a row buffer at `outrow[width - 1]`, which is `outrow[-1]` when the width is 0. The process crashes. ### Details The PPM parser reads width and height with no lower-bound check: - `src/PIL/PpmImagePlugin.py:119` The native `apply()` writes the row edges with no guard that the width is positive: - `src/_imagingmorph.c:81` sets `outrow[0] = outrow[width - 1] = 0;` `match()` and `get_on_pixels()` use the same edge-indexing pattern. ### PoC ```python from PIL import Image, ImageMorph # A width-0 image (also producible from a crafted PPM header). apply() indexes # outrow[width - 1] == outrow[-1] in native code. im = Image.new("L", (0, 5)) ImageMorph.MorphOp(op_name="dilation4").apply(im) ``` Run it: ``` $ python 03_poc.py Segmentation fault (core dumped) ``` Observed on a source build of commit `3e2ab96`. Under AddressSanitizer: ``` ==ERROR: AddressSanitizer: SEGV on unknown address (pc ... in apply) #0 apply src/_imagingmorph.c:81 SUMMARY: AddressSanitizer: SEGV src/_imagingmorph.c:81 in apply ``` With width 0 the `outrow[width - 1]` write lands on an unmapped page, so it surfaces as a SEGV pinned to the edge-write line rather than a redzone overflow. ### Impact Out-of-bounds write in a C extension. Affects any application that runs a morphology operation on an image opened from untrusted input. Result is a crash and possible memory corruption.
References
- github.com/python-pillow/Pillow/security/advisories/GHSA-58r4-6rv3-gfh8 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-112397 (opens in a new tab)
- github.com/python-pillow/Pillow/commit/18f7c0dfee93063c51db6ed0ca8c4da2999dcb64 (opens in a new tab)
- github.com/python-pillow/Pillow (opens in a new tab)
- github.com/python-pillow/Pillow/releases/tag/13.0.0 (opens in a new tab)