How severe is CVE-2021-27922?

CVE-2021-27922 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-2021-27922 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27922?

CVE-2021-27922 primarily affects Python Pillow. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-27922?

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-2021-27922 published?

CVE-2021-27922 was published on 2021-03-03 and last updated on 2026-06-17.

CVE-2021-27922

CVE-2021-27922 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-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Python Pillow
Published: 2021-03-03
Last modified: 2026-06-17

Description

Pillow before 8.1.2 allows attackers to cause a denial of service (memory consumption) because the reported size of a contained image is not properly checked for an ICNS container, and thus an attempted memory allocation can be very large.

Frequently asked questions

What is CVE-2021-27922?: Pillow before 8.1.2 allows attackers to cause a denial of service (memory consumption) because the reported size of a contained image is not properly checked for an ICNS container, and thus an attempted memory allocation can be very large.
How severe is CVE-2021-27922?: CVE-2021-27922 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-2021-27922 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27922?: CVE-2021-27922 primarily affects Python Pillow. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-27922?: 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-2021-27922 published?: CVE-2021-27922 was published on 2021-03-03 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

More vulnerabilities in Python Pillow

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