CVE-2026-6429 curl CVE debrief

Who should care

Defenders responsible for systems using libcurl with .netrc and HTTP redirects should assess exposure and review vendor advisory for CVE-2026-6429. This includes operators, platform administrators, vulnerability management teams, and security teams. They should verify libcurl usage in their environments and review compensating controls for exposed systems. Additionally, they should check relevant monitoring, detection, and logs for exposed assets that need

Why it matters

CVE-2026-6429: libcurl could leak passwords when using .netrc and following HTTP redirects, requiring defenders to assess exposure and review vendor advisory.

• Verify libcurl usage with .netrc and HTTP redirects
• Assess exposure to potential password leaks
• Review vendor advisory for CVE-2026-6429
• Update libcurl to version 8.20.0 or later

Technical summary

libcurl could leak the password used for the first host to the followed-to host under certain circumstances when asked to both use a .netrc file for credentials and to follow HTTP redirects. This vulnerability affects systems using libcurl with .netrc and HTTP redirects. The leak can occur when the followed-to host is not the intended target, potentially exposing sensitive information. Defenders should assess exposure and review vendor advisory for CVE-2026-6429 to mitigate this vulnerability. The vulnerability has been publicly disclosed and defenders should review the vendor advisory for CVE-2026-6429.

Defensive priority

Assess exposure where libcurl is used with .netrc and HTTP redirects

Recommended defensive actions

• Assess libcurl usage with .netrc and HTTP redirects
• Review vendor advisory for CVE-2026-6429
• Update libcurl to version 8.20.0 or later
• Verify libcurl usage in managed environments
• Review compensating controls for exposed systems
• Check relevant monitoring, detection, and logs for exposed assets
• Track exceptions and retest remediated assets

Evidence notes

Official CVE Program record and NIST NVD detail page provide information on CVE-2026-6429. Vendor advisory and product details are available. The CVE record was published on 2026-05-13T13:01:56.930Z and has not been modified since then. The vulnerability has been publicly disclosed and defenders should review the vendor advisory for CVE-2026-6429. Additional information can be found in the official CVE Program record and NIST NVD detail page.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.