PatchTheCVECVE-2026-87864: Enabling `CURLOPT_CRLF` causes curl to advertise the raw input byte count in the `IMAP APPEND {N}` literal whi
3
Routine
HIGH n/a
CVE-2026-87864 is a high-severity flaw (CVSS n/a) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | n/a (High) |
| EPSS exploit chance | 0.2% (top 90%) |
| CISA exploited list | No |
| Published | 2026-10-20 |
| Last modified | 2026-10-22 |
Publisher (CNA): curl
Timeline
- Published CVE record published
- Updated Record last modified
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Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.