All vulnerabilities

Servers and applications

CVE-2026-8927

When reusing a libcurl handle for sequential transfers driven by environment-variable proxy configuration, libcurl fails to clear the proxy authentication state between requests. Specifically, if the initial transfer authenticates against `proxyA` using Digest auth, a subsequent transfer routed through `proxyB` erroneously leaks the `Proxy-Authorization:` header intended solely for `proxyA`.

Severity
Critical 9.1
Published
3 Jul 2026
Last changed
15 Sept 2026
Added to UpHeron
21 Oct 2026
Fixed in
8.21.0
Sources
NVD

Affected software

SoftwareAffected versions
curlServers and applications · cpe:a:haxx:curl
  • From 7.12.0 before 8.21.0

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2026-8927
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2026-8927