CVE-2026-8458

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.

CVSS Metrics

• v3.1•MEDIUM•Score: 6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

EPSS Trends

Current EPSS score: 0.37%• Percentile: 31%

Techniques & Countermeasures

• CWE-488•Exposure of Data Element to Wrong Session

  The product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session.

Affected Systems

• alpine•curl

  ≥ 7.46.0, < 8.22.0-r0 | ≥ 7.46.0, < 8.21.0-r0

• chainguard•eco-python-curl

  < 8.21.0-r0

• chainguard•eco-python-curl-minimal

  < 8.21.0-r0

• chainguard•eco-python-curl-minimal-bin

  < 8.21.0-r0

• chainguard•eco-python-curl-minimal-dev

  < 8.21.0-r0

• chainguard•eco-python-curl-minimal-doc

  < 8.21.0-r0

• chainguard•eco-python-curl-minimal-static

  < 8.21.0-r0

• chainguard•eco-python-curl-nghttp2

  < 8.21.0-r0

• chainguard•eco-python-curl-nghttp2-bin

  < 8.21.0-r0

• chainguard•eco-python-curl-nghttp2-dev

  < 8.21.0-r0

• chainguard•eco-python-curl-nghttp2-static

  < 8.21.0-r0

• chainguard•libcurl4

  all

• wolfi•libcurl4

  all

• curl•curl

  8.20.0 | 8.19.0 | 8.18.0 | 8.17.0 | 8.16.0 | 8.15.0 | 8.14.1 | 8.14.0 | 8.13.0 | 8.12.1 | 8.12.0 | 8.11.1 | 8.11.0 | 8.10.1 | 8.10.0 | 8.9.1 | 8.9.0 | 8.8.0 | 8.7.1 | 8.7.0 | 8.6.0 | 8.5.0 | 8.4.0 | 8.3.0 | 8.2.1 | 8.2.0 | 8.1.2 | 8.1.1 | 8.1.0 | 8.0.1 | 8.0.0 | 7.88.1 | 7.88.0 | 7.87.0 | 7.86.0 | 7.85.0 | 7.84.0 | 7.83.1 | 7.83.0 | 7.82.0 | 7.81.0 | 7.80.0 | 7.79.1 | 7.79.0 | 7.78.0 | 7.77.0 | 7.76.1 | 7.76.0 | 7.75.0 | 7.74.0 | 7.73.0 | 7.72.0 | 7.71.1 | 7.71.0 | 7.70.0 | 7.69.1 | 7.69.0 | 7.68.0 | 7.67.0 | 7.66.0 | 7.65.3 | 7.65.2 | 7.65.1 | 7.65.0 | 7.64.1 | 7.64.0 | 7.63.0 | 7.62.0 | 7.61.1 | 7.61.0 | 7.60.0 | 7.59.0 | 7.58.0 | 7.57.0 | 7.56.1 | 7.56.0 | 7.55.1 | 7.55.0 | 7.54.1 | 7.54.0 | 7.53.1 | 7.53.0 | 7.52.1 | 7.52.0 | 7.51.0 | 7.50.3 | 7.50.2 | 7.50.1 | 7.50.0 | 7.49.1 | 7.49.0 | 7.48.0 | 7.47.1 | 7.47.0 | 7.46.0 | 7.45.0 | 7.44.0 | 7.43.0 | ≥ 7.43.0, < 8.14.2 | ≥ 8.15.0, < 8.16.1 | ≥ 8.17.0, < 8.20.1 | ≥ 97c272e5d173ad5f706443e2477f0a84f0044edd, < 5e99b73cf441d9c369768b9cd48b5389b9a2503d | 8.20.0 | 8.19.0 | 8.18.0 | 8.17.0 | 8.16.0 | 8.15.0 | 8.14.1 | 8.14.0 | 8.13.0 | 8.12.1 | 8.12.0 | 8.11.1 | 8.11.0 | 8.10.1 | 8.10.0 | 8.9.1 | 8.9.0 | 8.8.0 | 8.7.1 | 8.7.0 | 8.6.0 | 8.5.0 | 8.4.0 | 8.3.0 | 8.2.1 | 8.2.0 | 8.1.2 | 8.1.1 | 8.1.0 | 8.0.1 | 8.0.0 | 7.88.1 | 7.88.0 | 7.87.0 | 7.86.0 | 7.85.0 | 7.84.0 | 7.83.1 | 7.83.0 | 7.82.0 | 7.81.0 | 7.80.0 | 7.79.1 | 7.79.0 | 7.78.0 | 7.77.0 | 7.76.1 | 7.76.0 | 7.75.0 | 7.74.0 | 7.73.0 | 7.72.0 | 7.71.1 | 7.71.0 | 7.70.0 | 7.69.1 | 7.69.0 | 7.68.0 | 7.67.0 | 7.66.0 | 7.65.3 | 7.65.2 | 7.65.1 | 7.65.0 | 7.64.1 | 7.64.0 | 7.63.0 | 7.62.0 | 7.61.1 | 7.61.0 | 7.60.0 | 7.59.0 | 7.58.0 | 7.57.0 | 7.56.1 | 7.56.0 | 7.55.1 | 7.55.0 | 7.54.1 | 7.54.0 | 7.53.1 | 7.53.0 | 7.52.1 | 7.52.0 | 7.51.0 | 7.50.3 | 7.50.2 | 7.50.1 | 7.50.0 | 7.49.1 | 7.49.0 | 7.48.0 | 7.47.1 | 7.47.0 | 7.46.0 | 7.45.0 | 7.44.0 | 7.43.0

• debian•curl

  all | all | all | < 8.21.0~rc2-1

• haxx•curl

  ≥ 7.46.0, < 8.20.0

References (7)

• https://curl.se/docs/CVE-2026-8458.json
• https://curl.se/docs/CVE-2026-8458.html
• https://hackerone.com/reports/3721183
• https://security-tracker.debian.org/tracker/CVE-2026-8458
• https://security.alpinelinux.org/vuln/CVE-2026-8458
• https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8458.json
• https://nvd.nist.gov/vuln/detail/CVE-2026-8458