How severe is CVE-2021-26291?

CVE-2021-26291 has a CVSS 3.x base score of 9.1, 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 none.

Is CVE-2021-26291 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 9% (95th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26291?

CVE-2021-26291 primarily affects Apache Maven. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-26291?

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.

When was CVE-2021-26291 published?

CVE-2021-26291 was published on 2021-04-23 and last updated on 2026-06-17.

CVE-2021-26291

CVE-2021-26291 is a critical-severity vulnerability in Apache Maven with a CVSS 3.x base score of 9.1. 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-346.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 6.4
EPSS exploit prediction: 9% (95th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-346
Affected product: Apache Maven
Published: 2021-04-23
Last modified: 2026-06-17

Description

Apache Maven will follow repositories that are defined in a dependency’s Project Object Model (pom) which may be surprising to some users, resulting in potential risk if a malicious actor takes over that repository or is able to insert themselves into a position to pretend to be that repository. Maven is changing the default behavior in 3.8.1+ to no longer follow http (non-SSL) repository references by default. More details available in the referenced urls. If you are currently using a repository manager to govern the repositories used by your builds, you are unaffected by the risks present in the legacy behavior, and are unaffected by this vulnerability and change to default behavior. See this link for more information about repository management: https://maven.apache.org/repository-management.html

Frequently asked questions

What is CVE-2021-26291?: Apache Maven will follow repositories that are defined in a dependency’s Project Object Model (pom) which may be surprising to some users, resulting in potential risk if a malicious actor takes over that repository or is able to insert themselves into a position to pretend to be that repository. Maven is changing the default behavior in 3.8.1+ to no longer follow http (non-SSL) repository references by default. More details available in the referenced urls. If you are currently using a repository manager to govern the repositories used by your builds, you are unaffected by the risks present in the legacy behavior, and are unaffected by this vulnerability and change to default behavior. See this link for more information about repository management: https://maven.apache.org/repository-management.html
How severe is CVE-2021-26291?: CVE-2021-26291 has a CVSS 3.x base score of 9.1, 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 none.
Is CVE-2021-26291 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 9% (95th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26291?: CVE-2021-26291 primarily affects Apache Maven. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-26291?: 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.
When was CVE-2021-26291 published?: CVE-2021-26291 was published on 2021-04-23 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:apache:maven:*:*:*:*:*:*:*:*
cpe:2.3:a:quarkus:quarkus:*:*:*:*:*:*:*:*
cpe:2.3:a:oracle:financial_services_analytical_applications_infrastructure:*:*:*:*:*:*:*:*
cpe:2.3:a:oracle:goldengate_big_data_and_application_adapters:23.1:*:*:*:*:*:*:*

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