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.
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Redhat_linux | — | No solution exists | Oct 19, 2026 | Oct 14, 2026 |
| Ubuntu | — | Upgrade curl (Ubuntu Pro)Upgrade libcurl4-gnutls-devUpgrade libcurl3-gnutlsUpgrade libcurl3-nss (Ubuntu Pro)Upgrade libcurl3 (Ubuntu Pro)Upgrade libcurl3t64-gnutlsUpgrade libcurl3-gnutls (Ubuntu Pro)Upgrade libcurl4-openssl-dev (Ubuntu Pro)Upgrade libcurl4-nss-devUpgrade libcurl4t64Upgrade libcurl4-gnutls-dev (Ubuntu Pro)Upgrade libcurl4-openssl-devUpgrade libcurl3-nssUpgrade libcurl4 (Ubuntu Pro)Upgrade libcurl4-nss-dev (Ubuntu Pro)Upgrade libcurl4Upgrade curl | Oct 14, 2026 | Oct 14, 2026 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub