Use After Free in Curl
CVE-2026-10536
A use-after-free vulnerability exists in libcurl when an application configures an HTTP/2 stream-dependency tree via `CURLOPT_STREAM_DEPENDS` or `CURLOPT_STREAM_DEPENDS_E`, subsequently invokes `curl_easy_reset()`, and finally terminates the handle with `curl_easy_cleanup()`. During this final cleanup phase, libcurl attempts to access and modify an internal structure that was already freed during the reset operation.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (46.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.006 · change: -0.003
Affected products
Weakness classification (CWE)
References
- 2499f714-1537-4658-8207-48ae4bb9eae9 (Vendor Advisory)
- 2499f714-1537-4658-8207-48ae4bb9eae9 (Patch, Vendor Advisory)
- 2499f714-1537-4658-8207-48ae4bb9eae9 (Exploit, Third Party Advisory, Issue Tracking)
Frequently asked questions
- What is CVE-2026-10536?
- CVE-2026-10536 is a critical-severity vulnerability in Curl, classified under Use After Free. CVSS score: 9.8/10. Published 2026-07-03.
- How severe is CVE-2026-10536?
- Critical severity. CVSS v3 base score is 9.8 out of 10.