What’s Vulnerable › Vulnerabilities

CVE-2026-9080: UAF after pause in socket callback

• Severity: high (CVSS 7.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-07-03 · updated 2026-09-15
• Weakness: CWE-416

Description

Calling `curl_easy_pause()` within the event-based `CURLMOPT_SOCKETFUNCTION` callback triggers a use-after-free vulnerability, where libcurl attempts to store a flag using a dangling struct pointer immediately after that pointer's memory has been freed.

Affected products

• curl: from 8.13.0 before 8.21.0 — fixed in 8.21.0

How to fix

Upgrade to a fixed version: curl 8.21.0. Check the vendor advisory for mitigations.

References

• https://curl.se/docs/CVE-2026-9080.html
• https://curl.se/docs/CVE-2026-9080.json
• https://hackerone.com/reports/3749204
• https://hackerone.com/reports/3749204

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