CVE-2026-8458

MEDIUMCVSS 6.5/10EPSS 0.21%

Last modified

CVE-2026-8458 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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.. EPSS estimates a 0.21% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
6.5/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

EPSS Probability
0.21%

10.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
curlcurl>= 8.20.0, <= 8.20.0; >= 8.19.0, <= 8.19.0; >= 8.18.0, <= 8.18.0; >= 8.17.0, <= 8.17.0; >= 8.16.0, <= 8.16.0; >= 8.15.0, <= 8.15.0; >= 8.14.1, <= 8.14.1; >= 8.14.0, <= 8.14.0; >= 8.13.0, <= 8.13.0; >= 8.12.1, <= 8.12.1; >= 8.12.0, <= 8.12.0; >= 8.11.1, <= 8.11.1; >= 8.11.0, <= 8.11.0; >= 8.10.1, <= 8.10.1; >= 8.10.0, <= 8.10.0; >= 8.9.1, <= 8.9.1; >= 8.9.0, <= 8.9.0; >= 8.8.0, <= 8.8.0; >= 8.7.1, <= 8.7.1; >= 8.7.0, <= 8.7.0; >= 8.6.0, <= 8.6.0; >= 8.5.0, <= 8.5.0; >= 8.4.0, <= 8.4.0; >= 8.3.0, <= 8.3.0; >= 8.2.1, <= 8.2.1; >= 8.2.0, <= 8.2.0; >= 8.1.2, <= 8.1.2; >= 8.1.1, <= 8.1.1; >= 8.1.0, <= 8.1.0; >= 8.0.1, <= 8.0.1; >= 8.0.0, <= 8.0.0; >= 7.88.1, <= 7.88.1; >= 7.88.0, <= 7.88.0; >= 7.87.0, <= 7.87.0; >= 7.86.0, <= 7.86.0; >= 7.85.0, <= 7.85.0; >= 7.84.0, <= 7.84.0; >= 7.83.1, <= 7.83.1; >= 7.83.0, <= 7.83.0; >= 7.82.0, <= 7.82.0; >= 7.81.0, <= 7.81.0; >= 7.80.0, <= 7.80.0; >= 7.79.1, <= 7.79.1; >= 7.79.0, <= 7.79.0; >= 7.78.0, <= 7.78.0; >= 7.77.0, <= 7.77.0; >= 7.76.1, <= 7.76.1; >= 7.76.0, <= 7.76.0; >= 7.75.0, <= 7.75.0; >= 7.74.0, <= 7.74.0; >= 7.73.0, <= 7.73.0; >= 7.72.0, <= 7.72.0; >= 7.71.1, <= 7.71.1; >= 7.71.0, <= 7.71.0; >= 7.70.0, <= 7.70.0; >= 7.69.1, <= 7.69.1; >= 7.69.0, <= 7.69.0; >= 7.68.0, <= 7.68.0; >= 7.67.0, <= 7.67.0; >= 7.66.0, <= 7.66.0; >= 7.65.3, <= 7.65.3; >= 7.65.2, <= 7.65.2; >= 7.65.1, <= 7.65.1; >= 7.65.0, <= 7.65.0; >= 7.64.1, <= 7.64.1; >= 7.64.0, <= 7.64.0; >= 7.63.0, <= 7.63.0; >= 7.62.0, <= 7.62.0; >= 7.61.1, <= 7.61.1; >= 7.61.0, <= 7.61.0; >= 7.60.0, <= 7.60.0; >= 7.59.0, <= 7.59.0; >= 7.58.0, <= 7.58.0; >= 7.57.0, <= 7.57.0; >= 7.56.1, <= 7.56.1; >= 7.56.0, <= 7.56.0; >= 7.55.1, <= 7.55.1; >= 7.55.0, <= 7.55.0; >= 7.54.1, <= 7.54.1; >= 7.54.0, <= 7.54.0; >= 7.53.1, <= 7.53.1; >= 7.53.0, <= 7.53.0; >= 7.52.1, <= 7.52.1; >= 7.52.0, <= 7.52.0; >= 7.51.0, <= 7.51.0; >= 7.50.3, <= 7.50.3; >= 7.50.2, <= 7.50.2; >= 7.50.1, <= 7.50.1; >= 7.50.0, <= 7.50.0; >= 7.49.1, <= 7.49.1; >= 7.49.0, <= 7.49.0; >= 7.48.0, <= 7.48.0; >= 7.47.1, <= 7.47.1; >= 7.47.0, <= 7.47.0; >= 7.46.0, <= 7.46.0; >= 7.45.0, <= 7.45.0; >= 7.44.0, <= 7.44.0; >= 7.43.0, <= 7.43.0

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

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 score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.
How do I fix CVE-2026-8458?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST