Threat video1:00
CVE-2026-104269 ModSecurity Bypass: Detection & IOCs
ModSecurity ignores RFC 2231 filename* values that backends honour, so CRS upload rules miss them. 9 detection rules, 9 IOCs and a free Splunk SPL rule.
Read the full threat intel for CVE-2026-104269 ModSecurity Bypass: Detection & IOCs →
Chapters
- 0:00The hookModSecurity's upload filter has a bypass.
- 0:05The storyModSecurity ignores the extended filename parameter.
- 0:12Attack pathA parser mismatch lets uploads slip past WAF.
- 0:26AttributionNo threat actor is attributed.
- 0:31Indicators of compromise8 indicators to hunt: 3 file names and 5 package names.
- 0:37MITRE ATT&CK techniques5 ATT&CK techniques, from initial access to impact.
- 0:42Remediation12 remediation steps are listed, 4 of them immediate.
- 0:50Detection rules9 detection rules, in SPL, KQL and Sigma.
Transcript
0:00ModSecurity's upload filter has a bypass.
0:05ModSecurity ignores the extended filename parameter.
0:09Common backends honour it.
0:12A parser mismatch lets uploads slip past WAF.
0:16Common backends store the file under that name.
0:18If the folder runs scripts, that is remote code execution.
0:26No threat actor is attributed. Confidence: low.
0:318 indicators to hunt: 3 file names and 5 package names.
0:375 ATT&CK techniques, from initial access to impact.
0:4212 remediation steps are listed, 4 of them immediate.
0:509 detection rules, in SPL, KQL and Sigma.
0:56Threadlinqs. The unified security engineering platform.