# CVE-2026-61813: ModSecurity: Incorrect libcurl TLS hostname verification setting in HttpsClient::download

Status: published. Published: 2026-11-05. Updated: 2026-11-05.

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Prior to 2.9.15 and 3.0.17, the HttpsClient::download function in src/utils/https_client.cc sets libcurl CURLOPT_SSL_VERIFYHOST to 1 instead of the strict value 2L. Under adversary-in-the-middle and TLS interception conditions, this non-strict setting may weaken TLS peer identity validation and increase the risk of accepting a certificate for an unintended host. End-to-end exploitation is non-trivial in typical environments. This issue is fixed in versions 2.9.15 and 3.0.17.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- owasp-modsecurity / ModSecurity: < 2.9.15 (affected); >= 3.0.0, < 3.0.17 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 3.1: 3.7 (low); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-295

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-2vqc-36qp-ccmw (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/owasp-modsecurity/ModSecurity/commit/cce204806430e4848327aadeb9113e654631a0c1 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/owasp-modsecurity/ModSecurity/commit/edca70d853bfb725325137fa40d178beebc324fc (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v2.9.15 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.17 (CNA: GitHub_M; x_refsource_MISC)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-61813; retrieved 2026-11-05; source updated 2026-11-05

Revision: 5bb9e9a9a34fb0672088f8097dc8993ed9bb2c80b61ee32cf62c1f8e02a88f79

Canonical: https://y2.dev/cve/CVE-2026-61813

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