Command injection in cURL - CVE-2026-87864
Published: October 14, 2026
Vulnerability identifier: #VU155682
CSH Severity: Low
CVSS v4: 0 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-87864
CWE-ID: CWE-77
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to inject and execute IMAP commands within an authenticated session.
The vulnerability exists due to improper handling of a length parameter inconsistency in curl's IMAP APPEND implementation when processing uploads. A remote user can supply upload data whose line-ending conversion expands it beyond the advertised literal length to inject and execute IMAP commands within an authenticated session.
Exploitation requires CURLOPT_CRLF to be enabled.
Affected software
cURL
How to mitigate CVE-2026-87864
Install security update from vendor's website.
cURL - update to 8.22.0