redirect to SFTP or SCP bypasses host verification

Summary

A flaw in the curl command line tool's logic makes it only set SSH host verification options when interacting directly using SFTP or SCP, and not as a result of following a redirect.

Timeline

1. Oct 20, 2026, 7:59 PM UTCCVE published
2. Oct 29, 2026, 6:35 PM UTCCISA SSVC assessment

   Exploitation: poc · Automatable: no · Technical impact: total

3. Oct 29, 2026, 6:36 PM UTCRecord last updated

Affected versions

• curl curl

  From 8.22.0 · through 8.22.0; From 8.21.0 · through 8.21.0; From 8.20.0 · through 8.20.0; From 8.19.0 · through 8.19.0; From 8.18.0 · through 8.18.0; From 8.17.0 · through 8.17.0; From 8.16.0 · through 8.16.0; From 8.15.0 · through 8.15.0; From 8.14.1 · through 8.14.1; From 8.14.0 · through 8.14.0; From 8.13.0 · through 8.13.0; From 8.12.1 · through 8.12.1; From 8.12.0 · through 8.12.0; From 8.11.1 · through 8.11.1; From 8.11.0 · through 8.11.0; From 8.10.1 · through 8.10.1; From 8.10.0 · through 8.10.0; From 8.9.1 · through 8.9.1; From 8.9.0 · through 8.9.0; From 8.8.0 · through 8.8.0; From 8.7.1 · through 8.7.1; From 8.7.0 · through 8.7.0; From 8.6.0 · through 8.6.0; From 8.5.0 · through 8.5.0; From 8.4.0 · through 8.4.0; From 8.3.0 · through 8.3.0; From 8.2.1 · through 8.2.1; From 8.2.0 · through 8.2.0; From 8.1.2 · through 8.1.2; From 8.1.1 · through 8.1.1; From 8.1.0 · through 8.1.0; From 8.0.1 · through 8.0.1; From 8.0.0 · through 8.0.0; From 7.88.1 · through 7.88.1; From 7.88.0 · through 7.88.0; From 7.87.0 · through 7.87.0; From 7.86.0 · through 7.86.0; From 7.85.0 · through 7.85.0; From 7.84.0 · through 7.84.0; From 7.83.1 · through 7.83.1; From 7.83.0 · through 7.83.0; From 7.82.0 · through 7.82.0; From 7.81.0 · through 7.81.0

References 3