CVE-2025-15079 curl CVE debrief

Who should care

Defenders and administrators using libcurl for SSH-based transfers with SCP or SFTP should assess exposure, verify configurations, and prioritize updating libcurl to mitigate potential risks associated with this vulnerability. They should also review compensating controls for exposed systems and track exceptions while ensuring secure connections. Security teams and vulnerability management teams should also be aware of the potential impact on their systems

Why it matters

CVE-2025-15079 is a medium-severity vulnerability in libcurl that could cause it to mistakenly accept connections to hosts not present in the specified known_hosts file. Defenders and administrators using libcurl for SSH-based transfers with SCP or SFTP should assess exposure and verify configurations.

• Verify libcurl configurations to prevent potential security risks
• Update libcurl to ensure secure connections

Technical summary

libcurl could mistakenly accept connecting to hosts not present in the specified known_hosts file if they were added as recognized in the libssh global known_hosts file when using SSH-based transfers with SCP or SFTP. This issue affects libcurl when using SSH-based transfers with SCP or SFTP, potentially allowing unauthorized connections. The vulnerability has a medium severity and a CVSS score of 5.3, emphasizing the need for defenders to assess exposure and verify configurations. Affected systems may require updates to libcurl and review of SSH-based transfer configurations to mitigate potential risks.

Defensive priority

Defenders should prioritize verifying and updating libcurl to mitigate potential risks associated with this vulnerability.

Recommended defensive actions

• Verify libcurl version and configuration
• Update libcurl to the latest version
• Review SSH-based transfer configurations
• Check relevant monitoring, detection, and logs for exposed assets
• Track exceptions, retest remediated assets
• Confirm whether affected product deployments exist in managed environments
• Plan vendor-supported updates or mitigations through normal change control

Evidence notes

The CVE record and NVD entry provide details about the vulnerability in libcurl, but its actual impact, exploitation status, and affected scope remain unclear. Defenders should verify libcurl configurations, review SSH-based transfer configurations, and update libcurl to ensure secure connections. Evidence from the CVE Program and NVD suggests potential security risks, but further verification is needed.

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.