ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Prior to 3.0.16, the multipart/form-data request body parser in libmodsecurity silently removes embedded line breaks from non-file form-field values before exporting them to ARGS and ARGS_POST because src/request_body_processor/multipart.cc overwrites reserved bytes in m_reserve instead of appending the current buffer. This creates a parser differential between ModSecurity and backend applications that preserve line breaks in form fields, allowing rules that inspect ARGS or ARGS_POST to miss payloads whose dangerous syntax depends on a line break. This issue is fixed in version 3.0.16.
CVE-2026-52747
HIGHPre-NVD 8.68.6
EchelonGraph scoreLOW confidence
This high-severity CVE scores 8.6 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: secondary
8.6
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: —CVSS: 8.6Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.6
- EG Score
- 8.6(low)
- EPSS
- —
- KEV
- Not listed
Published
July 10, 2026
Last Modified
July 10, 2026
Advisory Details (3)
Auto-updated Jul 10, 2026🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available
Multipart form-data parser silently strips embedded line breaks from form-field values, enabling request-body inspection bypass · Advisory · owasp-modsecurity/ModSecurity · GitHub
https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-rcw9-2f5r-7p88github_release Patch Available
v3.0.16
Patch available: owasp-modsecurity/ModSecurity v3.0.16
https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.16github_commit
commit 875504c27581 (owasp-modsecurity/ModSecurity)
Fix landed in owasp-modsecurity/ModSecurity commit 875504c27581 — awaiting tagged release
https://github.com/owasp-modsecurity/ModSecurity/commit/875504c2758169c41be1ad2f0cc64d896b7815d7Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 3× in last 7d / 3× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-11 10:12 UTCEG score recompute
- 2026-07-10 21:53 UTCEG score recompute
- 2026-07-10 21:52 UTCMITRE cvelistV5first tracked
Frequently asked(4)
What is CVE-2026-52747?
CVE-2026-52747 is a high vulnerability published on July 10, 2026. ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Prior to 3.0.16, the multipart/form-data request body parser in libmodsecurity silently removes embedded line breaks from non-file form-field values before exporting them to ARGS and…
When was CVE-2026-52747 disclosed?
CVE-2026-52747 was first published in the National Vulnerability Database on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-52747?
CVE-2026-52747 has a CVSS v3 base score of 8.6 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-52747?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-52747, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-52747
Is Your Infrastructure Affected by CVE-2026-52747?
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