How severe is CVE-2021-3902?

CVE-2021-3902 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-3902 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3902?

CVE-2021-3902 affects Dompdf Project Dompdf. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-3902?

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

Does CVE-2021-3902 have an EU (EUVD) identifier?

Yes. CVE-2021-3902 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-3187.

When was CVE-2021-3902 published?

CVE-2021-3902 was published on 2024-11-15 and last updated on 2026-06-17.

CVE-2021-3902

CVE-2021-3902 is a critical-severity vulnerability in Dompdf Project Dompdf with a CVSS 3.x base score of 9.8. 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-611.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-3187
Weakness: CWE-611
Affected product: Dompdf Project Dompdf
Published: 2024-11-15
Last modified: 2026-06-17

Description

An improper restriction of external entities (XXE) vulnerability in dompdf/dompdf's SVG parser allows for Server-Side Request Forgery (SSRF) and deserialization attacks. This issue affects all versions prior to 2.0.0. The vulnerability can be exploited even if the isRemoteEnabled option is set to false. It allows attackers to perform SSRF, disclose internal image files, and cause PHAR deserialization attacks.

Frequently asked questions

What is CVE-2021-3902?: An improper restriction of external entities (XXE) vulnerability in dompdf/dompdf's SVG parser allows for Server-Side Request Forgery (SSRF) and deserialization attacks. This issue affects all versions prior to 2.0.0. The vulnerability can be exploited even if the isRemoteEnabled option is set to false. It allows attackers to perform SSRF, disclose internal image files, and cause PHAR deserialization attacks.
How severe is CVE-2021-3902?: CVE-2021-3902 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-3902 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3902?: CVE-2021-3902 affects Dompdf Project Dompdf. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-3902?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2021-3902 have an EU (EUVD) identifier?: Yes. CVE-2021-3902 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-3187.
When was CVE-2021-3902 published?: CVE-2021-3902 was published on 2024-11-15 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:dompdf_project:dompdf:*:*:*:*:*:*:*:*

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