Vulnerability
curl/libcurl: SSL out of buffer access
libcurl contains an out boundary access flaw in SSL related code. When allocating memory for a connection (the internal struct called `connectdata`), a certain amount of memory is allocated at the end of the struct to be used for SSL related structs. Those structs are used by the particular SSL library libcurl is built to use. The application can also tell libcurl which specific SSL library to use if it was built to support more than one. The math used to calculate the extra memory amount necessary for the SSL library was wrong on 32-bit systems, which made the allocated memory too small by 4 bytes. The last struct member of the last object within the memory area could then be outside of what was allocated. Accessing that member could lead to a crash or other undefined behaviors depending on what memory that is present there and how the particular SSL library decides to act on that memory content. Specifically the vulnerability is present if libcurl was built so that `sizeof(long long *) < sizeof(long long)` which as far as we are aware only happens in 32-bit builds.
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-2017-8818. 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