CVE & CISA-KEV Catalog

CVE-2026-8927

UNSCORED
NVD

Description

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`.

How to fix

Remediation Available
curlDebian
Fixed in:8.21.0~rc2-1CVE-2026-8927
curlUbuntu
Fixed in:7.35.0-1ubuntu2.20+esm20USN-8487-1
Fixed in:7.47.0-1ubuntu2.19+esm16USN-8487-1
Fixed in:7.58.0-2ubuntu3.24+esm9USN-8487-1
Fixed in:7.68.0-1ubuntu2.25+esm4USN-8487-1
Fixed in:7.81.0-1ubuntu1.25USN-8487-1
Fixed in:8.5.0-2ubuntu10.10USN-8487-1
Fixed in:8.14.1-2ubuntu1.4USN-8487-1
libcurl3Ubuntu
Fixed in:7.35.0-1ubuntu2.20+esm20USN-8487-1
Fixed in:7.47.0-1ubuntu2.19+esm16USN-8487-1
libcurl3-gnutlsUbuntu
Fixed in:7.35.0-1ubuntu2.20+esm20USN-8487-1
Fixed in:7.47.0-1ubuntu2.19+esm16USN-8487-1
Fixed in:7.58.0-2ubuntu3.24+esm9USN-8487-1
Fixed in:7.68.0-1ubuntu2.25+esm4USN-8487-1
Fixed in:7.81.0-1ubuntu1.25USN-8487-1
libcurl3-nssUbuntu
Fixed in:7.35.0-1ubuntu2.20+esm20USN-8487-1
Fixed in:7.47.0-1ubuntu2.19+esm16USN-8487-1
Fixed in:7.58.0-2ubuntu3.24+esm9USN-8487-1
Fixed in:7.68.0-1ubuntu2.25+esm4USN-8487-1
Fixed in:7.81.0-1ubuntu1.25USN-8487-1
libcurl3t64-gnutlsUbuntu
Fixed in:8.5.0-2ubuntu10.10USN-8487-1
Fixed in:8.14.1-2ubuntu1.4USN-8487-1
libcurl4Ubuntu
Fixed in:7.58.0-2ubuntu3.24+esm9USN-8487-1
Fixed in:7.68.0-1ubuntu2.25+esm4USN-8487-1
Fixed in:7.81.0-1ubuntu1.25USN-8487-1
libcurl4-gnutls-devUbuntu
Fixed in:7.35.0-1ubuntu2.20+esm20USN-8487-1
Fixed in:7.47.0-1ubuntu2.19+esm16USN-8487-1
Fixed in:7.58.0-2ubuntu3.24+esm9USN-8487-1
Fixed in:7.68.0-1ubuntu2.25+esm4USN-8487-1
Fixed in:7.81.0-1ubuntu1.25USN-8487-1
Fixed in:8.5.0-2ubuntu10.10USN-8487-1
Fixed in:8.14.1-2ubuntu1.4USN-8487-1
libcurl4-nss-devUbuntu
Fixed in:7.35.0-1ubuntu2.20+esm20USN-8487-1
Fixed in:7.47.0-1ubuntu2.19+esm16USN-8487-1
Fixed in:7.58.0-2ubuntu3.24+esm9USN-8487-1
Fixed in:7.68.0-1ubuntu2.25+esm4USN-8487-1
Fixed in:7.81.0-1ubuntu1.25USN-8487-1
libcurl4-openssl-devUbuntu
Fixed in:7.35.0-1ubuntu2.20+esm20USN-8487-1
Fixed in:7.47.0-1ubuntu2.19+esm16USN-8487-1
Fixed in:7.58.0-2ubuntu3.24+esm9USN-8487-1
Fixed in:7.68.0-1ubuntu2.25+esm4USN-8487-1
Fixed in:7.81.0-1ubuntu1.25USN-8487-1
Fixed in:8.5.0-2ubuntu10.10USN-8487-1
Fixed in:8.14.1-2ubuntu1.4USN-8487-1
libcurl4t64Ubuntu
Fixed in:8.5.0-2ubuntu10.10USN-8487-1
Fixed in:8.14.1-2ubuntu1.4USN-8487-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3.1 Vector

No CVSS vector data available.

Exploit Intelligence

0.25%probability of exploitation in 30 days
16thpercentile

Low risk: more likely to be exploited than 16% of all known CVEs.

References

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Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-03.