Is there a public exploit for CVE-2026-73856?

No public exploit for CVE-2026-73856 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-73856?

CVE-2026-73856 scores CVSS 8.6 (v3.1), rated high. EPSS puts the chance of exploitation in the next 30 days at 0.57%.

What does CVE-2026-73856 affect?

CVE-2026-73856 affects owasp-modsecurity ModSecurity.

8.6 High

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx.

CVE-2026-73856

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.0 until 3.0.17, src/transaction.cc compares a response Content-Type value against SecResponseBodyMimeType entries case-sensitively. A mixed-case response media type that is semantically equivalent to a configured lowercase type can therefore be treated as unconfigured, causing ModSecurity to skip RESPONSEBODY inspection. An unauthenticated requester can then receive response content that a phase 4 rule would otherwise block, including sensitive error or debug data. This issue is fixed in version 3.0.17.

Assessment

CVSS: 8.6 (v3.1)
Severity: High
EPSS: 0.57% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 5 November 2026
Last updated: 9 November 2026
Affected: owasp-modsecurity · ModSecurity
Assigner: GitHub_M

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

At the source

EUVD (ENISA)

References

Community proofs of concept

No community proof of concept yet. If you have one for a published vulnerability and the right to share it, add it below — it will appear here once reviewed.

Submit a proof of concept

Only for publicly disclosed vulnerabilities, and only material from testing you were authorised to perform. This platform does not buy, sell, or broker exploits — see earning from vulnerability research for legitimate bounty programs. Submissions are reviewed before they appear. Text only; do not include live credentials, personal data, or anything targeting systems you are not permitted to test.

Title *

Proof of concept *

Write-up (optional)

Affected versions (optional)

Name or handle (optional)

References (optional, one URL per line)

Licence for your contribution *

Private contact (optional, never shown)

Before you submit * This vulnerability is already publicly disclosed (it has a published CVE). This material comes only from testing I was authorised to perform. I have the legal right to publish this content and am not breaching any agreement by doing so. It contains no live credentials, personal data, or anything targeting systems I am not authorised to test. I understand it will be reviewed before it appears publicly and may be rejected. I agree to the submission terms.

What is 2 + 6? *

Query this programmatically

Agents can read this through the MCP endpoint, or over HTTP:

curl https://cve.zerocrew.in/api/cve/CVE-2026-73856