CVE-2026-92389
libcurl's TFTP state machine fails to validate state transitions against the requested transfer…
- Risk score
- 57/100
- CVSS
- 8.1 v3.1
- Exploit chance (30 days)
- 0.3%
- Published
- 20 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- libcurl's TFTP state machine fails to validate state transitions against the requested transfer direction, accepting opening server responses for both reads and writes interchangeably. A malicious TFTP server can respond to a download request in a way that forces the client into transmit mode, prompting libcurl to con…
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 8.1 high
- Remotely exploitable without logging in
References
Original description
libcurl's TFTP state machine fails to validate state transitions against the requested transfer direction, accepting opening server responses for both reads and writes interchangeably. A malicious TFTP server can respond to a download request in a way that forces the client into transmit mode, prompting libcurl to consume and transmit data from the handle's persistent `CURLOPT_READDATA` pointer - including data remaining from unrelated prior operations, such as an HTTP POST request executed on a reused handle.
Last activity 20 Oct 2026. Patch Forecast updates every hour.