How severe is CVE-2026-8458?

CVE-2026-8458 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-8458 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-2026-8458?

CVE-2026-8458 affects Haxx Curl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-8458?

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

When was CVE-2026-8458 published?

CVE-2026-8458 was published on 2026-07-03 and last updated on 2026-09-15.

CVE-2026-8458

CVE-2026-8458 is a medium-severity vulnerability in Haxx Curl with a CVSS 3.x base score of 6.5. 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-488.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-488
Affected product: Haxx Curl
Published: 2026-07-03
Last modified: 2026-09-15

Description

libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different "services". libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different services.

Frequently asked questions

What is CVE-2026-8458?: libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different "services". libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different services.
How severe is CVE-2026-8458?: CVE-2026-8458 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-8458 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-2026-8458?: CVE-2026-8458 affects Haxx Curl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-8458?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-8458 published?: CVE-2026-8458 was published on 2026-07-03 and last updated on 2026-09-15.

References

Affected products (1)

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*

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CVE-2024-27455 — Critical (CVSS 9.1): In the Bentley ALIM Web application, certain configuration settings can cause exposure of a user's ALIM session token…
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Browse all CWE-488 vulnerabilities →