Answer in brief
CVE-2026-1965 records a Unknown severity vulnerability in bad reuse of HTTP Negotiate connection. The current sources do not mark it as known exploited. The current feed maps curl/curl (generic), curl/curl (generic), curl/curl (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps curl/curl (generic), curl/curl (generic), curl/curl (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| curl/curlgeneric | >=7.10.6 <8.14.2 || >=8.15.0 <8.16.1 || >=8.17.0 <8.19.0 | 8.14.2, 8.16.1, 8.19.0 |
| curl/curlgeneric | >=e56ae1426cb7a0a4a427cf8d6099a821fdaae428 <f1a39f221d57354990e3eeeddc3404aede2aff70 | f1a39f221d57354990e3eeeddc3404aede2aff70 |
| curl/curlgeneric | 8.18.0 || 8.17.0 || 8.16.0 || 8.15.0 || 8.14.1 || 8.14.0 || 8.13.0 || 8.12.1 || 8.12.0 || 8.11.1 || 8.11.0 || 8.10.1 || 8.10.0 || 8.9.1 || 8.9.0 || 8.8.0 || 8.7.1 || 8.7.0 || 8.6.0 || 8.5.0 || 8.4.0 || 8.3.0 || 8.2.1 || 8.2.0 || 8.1.2 || 8.1.1 || 8.1.0 || 8.0.1 || 8.0.0 || 7.88.1 || 7.88.0 || 7.87.0 || 7.86.0 || 7.85.0 || 7.84.0 || 7.83.1 || 7.83.0 || 7.82.0 || 7.81.0 || 7.80.0 || 7.79.1 || 7.79.0 || 7.78.0 || 7.77.0 || 7.76.1 || 7.76.0 || 7.75.0 || 7.74.0 || 7.73.0 || 7.72.0 || 7.71.1 || 7.71.0 || 7.70.0 || 7.69.1 || 7.69.0 || 7.68.0 || 7.67.0 || 7.66.0 || 7.65.3 || 7.65.2 || 7.65.1 || 7.65.0 || 7.64.1 || 7.64.0 || 7.63.0 || 7.62.0 || 7.61.1 || 7.61.0 || 7.60.0 || 7.59.0 || 7.58.0 || 7.57.0 || 7.56.1 || 7.56.0 || 7.55.1 || 7.55.0 || 7.54.1 || 7.54.0 || 7.53.1 || 7.53.0 || 7.52.1 || 7.52.0 || 7.51.0 || 7.50.3 || 7.50.2 || 7.50.1 || 7.50.0 || 7.49.1 || 7.49.0 || 7.48.0 || 7.47.1 || 7.47.0 || 7.46.0 || 7.45.0 || 7.44.0 || 7.43.0 || 7.42.1 || 7.42.0 || 7.41.0 || 7.40.0 || 7.39.0 || 7.38.0 || 7.37.1 || 7.37.0 || 7.36.0 || 7.35.0 || 7.34.0 || 7.33.0 || 7.32.0 || 7.31.0 || 7.30.0 || 7.29.0 || 7.28.1 || 7.28.0 || 7.27.0 || 7.26.0 || 7.25.0 || 7.24.0 || 7.23.1 || 7.23.0 || 7.22.0 || 7.21.7 || 7.21.6 || 7.21.5 || 7.21.4 || 7.21.3 || 7.21.2 || 7.21.1 || 7.21.0 || 7.20.1 || 7.20.0 || 7.19.7 || 7.19.6 || 7.19.5 || 7.19.4 || 7.19.3 || 7.19.2 || 7.19.1 || 7.19.0 || 7.18.2 || 7.18.1 || 7.18.0 || 7.17.1 || 7.17.0 || 7.16.4 || 7.16.3 || 7.16.2 || 7.16.1 || 7.16.0 || 7.15.5 || 7.15.4 || 7.15.3 || 7.15.2 || 7.15.1 || 7.15.0 || 7.14.1 || 7.14.0 || 7.13.2 || 7.13.1 || 7.13.0 || 7.12.3 || 7.12.2 || 7.12.1 || 7.12.0 || 7.11.2 || 7.11.1 || 7.11.0 || 7.10.8 || 7.10.7 || 7.10.6 | Not reported |
Published upstream
Mar 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 15, 2026
libcurl can in some circumstances reuse the wrong connection when asked to do an Negotiate-authenticated HTTP or HTTPS request. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criterion must first be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different credentials. One underlying reason being that Negotiate sometimes authenticates *connections* and not *requests*, contrary to how HTTP is designed to work. An application that allows Negotiate authentication to a server (that responds wanting Negotiate) with `user1:password1` and then does another operation to the same server also using Negotiate but with `user2:password2` (while the previous connection is still alive) - the second request wrongly reused the same connection and since it then sees that the Negotiate negotiation is already made, it sends the request over that connection thinking it uses the user2 credentials when it is in fact still using the connection authenticated for user1... The set of authentication methods to use is set with `CURLOPT_HTTPAUTH`. Applications can disable libcurl's reuse of connections and thus mitigate this problem, by using one of the following libcurl options to alter how connections are or are not reused: `CURLOPT_FRESH_CONNECT`, `CURLOPT_MAXCONNECTS` and `CURLMOPT_MAX_HOST_CONNECTIONS` (if using the curl_multi API).
Quoted source text, attributed separately from HOL analysis.