Medium · published January 8, 2026
When doing TLS related transfers with reused easy or multi handles and
altering the `CURLSSLOPT_NO_PARTIALCHAIN` option, libcurl could accidentally
reuse a CA store cached in memory for which the partial chain option was
reversed. Contrary to the user's wishes and expectations. This could make
libcurl find and accept a trust chain that it otherwise would not.
| Product | Versions | Fixed in |
|---|---|---|
| haxx/curl | ≥ 7.87.0, < 8.18.0 | 8.18.0 |