How severe is CVE-2024-25622?

CVE-2024-25622 has a CVSS 3.x base score of 3.1, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2024-25622 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-25622?

CVE-2024-25622 affects Dena H2o. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2024-25622?

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

Does CVE-2024-25622 have an EU (EUVD) identifier?

Yes. CVE-2024-25622 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-22943.

When was CVE-2024-25622 published?

CVE-2024-25622 was published on 2024-10-11 and last updated on 2026-06-17.

CVE-2024-25622

CVE-2024-25622 is a low-severity vulnerability in Dena H2o with a CVSS 3.x base score of 3.1. 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-670.

Key facts

Severity: Low (CVSS 3.x base score 3.1)
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-22943
Weakness: CWE-670
Affected product: Dena H2o
Published: 2024-10-11
Last modified: 2026-06-17

Description

h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. The configuration directives provided by the headers handler allows users to modify the response headers being sent by h2o. The configuration file of h2o has scopes, and the inner scopes (e.g., path level) are expected to inherit the configuration defined in outer scopes (e.g., global level). However, if a header directive is used in the inner scope, all the definition in outer scopes are ignored. This can lead to headers not being modified as expected. Depending on the headers being added or removed unexpectedly, this behavior could lead to unexpected client behavior. This vulnerability is fixed in commit 123f5e2b65dcdba8f7ef659a00d24bd1249141be.

Frequently asked questions

What is CVE-2024-25622?: h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. The configuration directives provided by the headers handler allows users to modify the response headers being sent by h2o. The configuration file of h2o has scopes, and the inner scopes (e.g., path level) are expected to inherit the configuration defined in outer scopes (e.g., global level). However, if a header directive is used in the inner scope, all the definition in outer scopes are ignored. This can lead to headers not being modified as expected. Depending on the headers being added or removed unexpectedly, this behavior could lead to unexpected client behavior. This vulnerability is fixed in commit 123f5e2b65dcdba8f7ef659a00d24bd1249141be.
How severe is CVE-2024-25622?: CVE-2024-25622 has a CVSS 3.x base score of 3.1, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2024-25622 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-25622?: CVE-2024-25622 affects Dena H2o. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-25622?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-25622 have an EU (EUVD) identifier?: Yes. CVE-2024-25622 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-22943.
When was CVE-2024-25622 published?: CVE-2024-25622 was published on 2024-10-11 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:dena:h2o:*:*:*:*:*:*:*:*

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