6.9

CVE-2026-112898: python-pillow pillow Use of Uninitialized Variable

CVSS: 6.9v4.0MediumReceived
AliasesDEBIAN-CVE-2026-112898
Published 19-10-2026Last modified 19-10-2026

Vulnerability summary

CVE-2026-112898 is a medium (CVSS 6.9) Use of Uninitialized Variable vulnerability in python-pillow pillow. EPSS estimates a 0.29% chance of exploitation in the next 30 days, higher than 20.4% of scored vulnerabilities.

Overall risk
28/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.9/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.29%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 19-10-2026
    PublishedVulnerability first disclosed.

Description

Pillow is a Python imaging library. From 9.1.0 until 13.0.0, Pillow can disclose uninitialized stack memory when Image.quantize() uses an empty palette. ImagingPaletteCacheUpdate() leaves a local cache array uninitialized when the palette has zero entries, and the conversion path emits those bytes as output pixel indices. An attacker who controls the palette image can obtain stack contents from a returned PNG or GIF. This can disclose addresses and stack-canary data without an out-of-bounds access, memory corruption, or process crash. This issue is fixed in version 13.0.0.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.29%

Chance of exploitation in the next 30 days

Percentile

20%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

20-10-202620-10-2026
EPSS score
0.29%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • pillowAll versions (No fix recorded)
Python-pillow1 product

2 vendors · 2 products

References

4 links