CVE-2026-87864
Published Oct 20, 2026
Description
Enabling `CURLOPT_CRLF` causes curl to advertise the raw input byte count in the `IMAP APPEND {N}` literal while transmitting line-ending expanded data. The server reads only $N$ bytes for the payload, causing the remaining overflow bytes to be interpreted and executed as pipelined IMAP commands within the authenticated session.
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References
Frequently Asked Questions
What is CVE-2026-87864? +
Enabling `CURLOPT_CRLF` causes curl to advertise the raw input byte count in
the `IMAP APPEND {N}` literal while transmitting line-ending expanded data.
The server reads only $N$ bytes for the payload, causing the remaining
overflow bytes to be interpreted and executed as pipelined IMAP commands
within the authenticated session.
How do I check if I'm vulnerable to CVE-2026-87864? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.