Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
The tornado package, versions before 6.5.7, is affected when an application uses CurlAsyncHTTPClient and issues requests with differing per-request options on a shared client. An attacker who can influence the destination of such a request (for example a user-supplied URL or a user-controlled proxy setting) can receive a client TLS certificate handshake or proxy basic-auth credentials intended for another host. Upgrade to tornado 6.5.7 or later; until then, use a separate CurlAsyncHTTPClient instance per credential set.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 8.2 | High | 4.0 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N | CNA (VulnCheck) |
- CISA KEV Not listed.
- EPSS 0.0024, the 15th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:10 UTC First seen by agentprime
- 31 Oct 2026, 14:10 UTC Confirmed by OSV