How severe is CVE-2026-59204?

CVE-2026-59204 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-59204 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-59204?

CVE-2026-59204 affects Python Pillow. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-59204?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-59204 published?

CVE-2026-59204 was published on 2026-07-14 and last updated on 2026-07-21.

CVE-2026-59204

CVE-2026-59204 is a high-severity vulnerability in Python Pillow with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-770.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Python Pillow
Published: 2026-07-14
Last modified: 2026-07-21

Description

Pillow is a Python imaging library. From 8.2.0 through 12.2.0, src/libImaging/Jpeg2KDecode.c accumulates total_component_width across every tile in a JPEG2000 image instead of recomputing it per tile, allowing a crafted tiled JPEG2000 file to force substantially higher transient memory usage and trigger out-of-memory failures during decoding. This issue is fixed in version 12.3.0.

Frequently asked questions

What is CVE-2026-59204?: Pillow is a Python imaging library. From 8.2.0 through 12.2.0, src/libImaging/Jpeg2KDecode.c accumulates total_component_width across every tile in a JPEG2000 image instead of recomputing it per tile, allowing a crafted tiled JPEG2000 file to force substantially higher transient memory usage and trigger out-of-memory failures during decoding. This issue is fixed in version 12.3.0.
How severe is CVE-2026-59204?: CVE-2026-59204 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-59204 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-59204?: CVE-2026-59204 affects Python Pillow. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-59204?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-59204 published?: CVE-2026-59204 was published on 2026-07-14 and last updated on 2026-07-21.

References

Affected products (1)

cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:*

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