How severe is CVE-2026-55380?

CVE-2026-55380 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-2026-55380 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-55380?

CVE-2026-55380 affects Python Pillow. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-55380?

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-2026-55380 published?

CVE-2026-55380 was published on 2026-07-06 and last updated on 2026-07-07.

CVE-2026-55380

CVE-2026-55380 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-789.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (26th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-789
Affected product: Python Pillow
Published: 2026-07-06
Last modified: 2026-07-07

Description

Pillow is a Python imaging library. Prior to 12.3.0, PIL/GdImageFile.py GdImageFile._open() read image dimensions from the GD 2.x header and stored them in self._size without calling Image._decompression_bomb_check(), allowing a crafted .gd file to trigger excessive C-heap allocation when loaded. This issue is fixed in version 12.3.0.

Frequently asked questions

What is CVE-2026-55380?: Pillow is a Python imaging library. Prior to 12.3.0, PIL/GdImageFile.py GdImageFile._open() read image dimensions from the GD 2.x header and stored them in self._size without calling Image._decompression_bomb_check(), allowing a crafted .gd file to trigger excessive C-heap allocation when loaded. This issue is fixed in version 12.3.0.
How severe is CVE-2026-55380?: CVE-2026-55380 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-2026-55380 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-55380?: CVE-2026-55380 affects Python Pillow. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-55380?: 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-2026-55380 published?: CVE-2026-55380 was published on 2026-07-06 and last updated on 2026-07-07.

References

Affected products (1)

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

More vulnerabilities in Python Pillow

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