How severe is CVE-2026-64607?

CVE-2026-64607 has a CVSS 3.x base score of 5.3, rated medium 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 low.

Is CVE-2026-64607 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-64607?

CVE-2026-64607 affects Apache Httpclient. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-64607?

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

When was CVE-2026-64607 published?

CVE-2026-64607 was published on 2026-07-31 and last updated on 2026-08-13.

CVE-2026-64607

CVE-2026-64607 is a medium-severity vulnerability in Apache Httpclient with a CVSS 3.x base score of 5.3. 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-772.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-772
Affected product: Apache Httpclient
Published: 2026-07-31
Last modified: 2026-08-13

Description

HttpClient based on the classic i/o model fails to correctly release the underlying connection back to the connection manager if it encounters an invalid or unsupported `Content-Encoding` header value in the response message. Please note this defect does not affect HttpClient based on the async i/o model. This issue affects Apache HttpComponents Client: from 5.0-alpha1 through 5.6.2.

Frequently asked questions

What is CVE-2026-64607?: HttpClient based on the classic i/o model fails to correctly release the underlying connection back to the connection manager if it encounters an invalid or unsupported `Content-Encoding` header value in the response message. Please note this defect does not affect HttpClient based on the async i/o model. This issue affects Apache HttpComponents Client: from 5.0-alpha1 through 5.6.2.
How severe is CVE-2026-64607?: CVE-2026-64607 has a CVSS 3.x base score of 5.3, rated medium 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 low.
Is CVE-2026-64607 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-64607?: CVE-2026-64607 affects Apache Httpclient. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-64607?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-64607 published?: CVE-2026-64607 was published on 2026-07-31 and last updated on 2026-08-13.

References

Affected products (1)

cpe:2.3:a:apache:httpclient:*:*:*:*:*:*:*:*

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