CVE-2026-87864

IMAP APPEND plus CRLF conversion command injection

HIGH
8.1
CVSS Score
Published: October 20, 2026 at 08:13 PM UTC
Updated: October 30, 2026 at 12:16 PM UTC
1 product affected across 1 vendorCurl

Using curl by curl?

Get instant alerts when new vulnerabilities affect curl - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH8.1
Exploit prediction
EPSS 0.8%
SSVC
PoC

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.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.1HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-130

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card