CVE-2026-59197
Heap out-of-bounds write in Pillow rank-filter (ImageFilter.RankFilter) with large odd filter size.
Is CVE-2026-59197 being exploited?
Not confirmed. CVE-2026-59197 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.45% probability of exploitation in the next 30 days.
How severe is CVE-2026-59197?
CVE-2026-59197 is rated High with a CVSS score of 8.2. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-59197?
Yes. A fix has been recorded for CVE-2026-59197. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-59197 affect?
CVE-2026-59197 affects Pillow < 12.3.0, Python apps using PIL/Pillow, Image-processing services accepting untrusted images. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-59197?
Upgrade Pillow to >=12.3.0 and block untrusted image uploads until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Crafted image with large odd filter size can cause heap OOB write, leading to crashes or potential remote code execution when processed.
Immediate action required
- affected< 12.3.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.