Vulnerability
curl/libcurl: URL unescape heap overflow via integer truncation
The URL percent-encoding decode function in libcurl is called `curl_easy_unescape`. Internally, even if this function would be made to allocate a destination buffer larger than 2GB, it would return that new length in a signed 32-bit integer variable, thus the length would get either truncated only or both truncated and turned negative. That could then lead to libcurl writing outside of its heap based buffer. This can be triggered by a user on a 64-bit system if the user can send in a custom (large) URL to a libcurl using program.
No CVSS 3.x base score yet. Since April 2026 NVD only enriches priority CVEs (KEV, federal and critical software), so most CVEs are scored only if the assigning CNA included a score in the CVE record, or by GHSA for open-source packages. Last record update .
For interim severity, fall back on KEV / EXPLOIT signals and the EPSS percentile (lower panel). Re-check this CVE after one cron tick — the score lands automatically when the source publishes.
Mid-pack — moderate exploitation likelihood.
No VEX statements published for CVE-2016-8622. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.
No exploitation, limited impact or prevalence