HTTP request injection via unescaped method value
Published Mar 17, 2026 · Updated Mar 17, 2026
CRLF injection in libsoup on Red Hat Enterprise Linux 7 through 10 allows remote attackers to inject HTTP headers and request data. soup_message_new() passes its method value to g_string_append_printf() without rejecting CRLF characters while constructing the HTTP/1.x request line. Exploitation requires an application path that lets the attacker control the method argument; successful injection alters outbound request headers or appends request data.
Summary
What happened
CRLF injection in libsoup on Red Hat Enterprise Linux 7 through 10 allows remote attackers to inject HTTP headers and request data. soup_message_new() passes its method value to g_string_append_printf() without rejecting CRLF characters while constructing the HTTP/1.x request line. Exploitation requires an application path that lets the attacker control the method argument; successful injection alters outbound request headers or appends request data.
The record
- CVE
- CVE-2026-3633
- Published
- Mar 17, 2026
- Updated
- Mar 17, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Enterprise Linux 10
- Classifications
- CWE-93
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 17, 2026CVE publishedPublication date reported by the CVE source.
- Mar 17, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- CRLF_inj_in_method.cproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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