CVE-2026-10536
CRITICAL
Published Jul 3, 2026
Modified Jul 6, 2026
Description
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.
CVSS v3.1 Score
9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS — Exploit Prediction
0.0021
Probability of exploitation
0.11%
Percentile rank
EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.
References
Frequently Asked Questions
What is 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. It has a CVSS v3.1 base score of 9.8 (CRITICAL).
How severe is CVE-2026-10536? +
CVE-2026-10536 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0021, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-10536? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.