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Critical 9.1Published Jul 3, 2026

CVE-2026-8927When reusing a libcurl handle for sequential transfers driven by environment-variable proxy configuration, libcurl fails to clear the proxy authentication state between requests.

Updated under an hour ago ()

Does this affect you?

It affects haxx curl. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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`.

CVSS
9.1 CRITICAL (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness (CWE)
CWE-294
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Not given
NVD analysis
Modified
Record last updated
Sep 15, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
haxx curl
haxx:curl
from 7.12.0 before 8.21.0
NVD

References

  • patch, vendor-advisory
  • vendor-advisory
  • exploit, issue-tracking, third-party-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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