How severe is CVE-2021-21236?

CVE-2021-21236 has a CVSS 3.x base score of 5.7, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-21236 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21236?

CVE-2021-21236 affects Courtbouillon Cairosvg. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21236?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-21236 published?

CVE-2021-21236 was published on 2021-01-06 and last updated on 2026-06-17.

CVE-2021-21236

CVE-2021-21236 is a medium-severity vulnerability in Courtbouillon Cairosvg with a CVSS 3.x base score of 5.7. 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-400.

Key facts

Severity: Medium (CVSS 3.x base score 5.7)
CVSS v2: 4.3
EPSS exploit prediction: 1% (71st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Courtbouillon Cairosvg
Published: 2021-01-06
Last modified: 2026-06-17

Description

CairoSVG is a Python (pypi) package. CairoSVG is an SVG converter based on Cairo. In CairoSVG before version 2.5.1, there is a regular expression denial of service (REDoS) vulnerability. When processing SVG files, the python package CairoSVG uses two regular expressions which are vulnerable to Regular Expression Denial of Service (REDoS). If an attacker provides a malicious SVG, it can make cairosvg get stuck processing the file for a very long time. This is fixed in version 2.5.1. See Referenced GitHub advisory for more information.

Frequently asked questions

What is CVE-2021-21236?: CairoSVG is a Python (pypi) package. CairoSVG is an SVG converter based on Cairo. In CairoSVG before version 2.5.1, there is a regular expression denial of service (REDoS) vulnerability. When processing SVG files, the python package CairoSVG uses two regular expressions which are vulnerable to Regular Expression Denial of Service (REDoS). If an attacker provides a malicious SVG, it can make cairosvg get stuck processing the file for a very long time. This is fixed in version 2.5.1. See Referenced GitHub advisory for more information.
How severe is CVE-2021-21236?: CVE-2021-21236 has a CVSS 3.x base score of 5.7, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-21236 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21236?: CVE-2021-21236 affects Courtbouillon Cairosvg. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21236?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-21236 published?: CVE-2021-21236 was published on 2021-01-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:courtbouillon:cairosvg:*:*:*:*:*:*:*:*

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