How severe is CVE-2026-71290?

CVE-2026-71290 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-2026-71290 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-71290?

CVE-2026-71290 affects Apache Httpclient. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-71290?

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-2026-71290 published?

CVE-2026-71290 was published on 2026-08-11 and last updated on 2026-08-17.

CVE-2026-71290

CVE-2026-71290 is a critical-severity vulnerability in Apache Httpclient 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-295.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Apache Httpclient
Published: 2026-08-11
Last modified: 2026-08-17

Description

Improper TLS hostname verification vulnerability in Apache HttpComponents Client 5.4 or newer. HostnameVerificationPolicy#BUILTIN setting has no effect when used with the async version of HttpClient. An attacker that can intercept and modify traffic between the client and the server can impersonate the server by presenting a valid certificate for a different domain. Please note the classic version of HttpClient is not affected by this vulnerability. Affected users are recommended to upgrade to at least version 5.6.4, which fixes the issue.

Frequently asked questions

What is CVE-2026-71290?: Improper TLS hostname verification vulnerability in Apache HttpComponents Client 5.4 or newer. HostnameVerificationPolicy#BUILTIN setting has no effect when used with the async version of HttpClient. An attacker that can intercept and modify traffic between the client and the server can impersonate the server by presenting a valid certificate for a different domain. Please note the classic version of HttpClient is not affected by this vulnerability. Affected users are recommended to upgrade to at least version 5.6.4, which fixes the issue.
How severe is CVE-2026-71290?: CVE-2026-71290 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-2026-71290 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-71290?: CVE-2026-71290 affects Apache Httpclient. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-71290?: 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-2026-71290 published?: CVE-2026-71290 was published on 2026-08-11 and last updated on 2026-08-17.

References

Affected products (1)

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

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