Vulnerability · Published Nov 5, 2026 · Assigned by GitHub_M
CVE-2026-61813ModSecurity: Incorrect libcurl TLS hostname verification setting in HttpsClient::download
Low 3.7
In plain English
A low-severity improper certificate validation in ModSecurity from owasp-modsecurity. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities).
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | modsecurity | no fix listed | DEBIAN-CVE-2026-61813 |
| Debian:13 | modsecurity | no fix listed | DEBIAN-CVE-2026-61813 |
| Debian:14 | modsecurity | no fix listed | DEBIAN-CVE-2026-61813 |
| Debian:12 | modsecurity-apache | no fix listed | DEBIAN-CVE-2026-61813 |
| Debian:13 | modsecurity-apache | no fix listed | DEBIAN-CVE-2026-61813 |
| Debian:14 | modsecurity-apache | no fix listed | DEBIAN-CVE-2026-61813 |
| Ubuntu:22.04:LTS | modsecurity | no fix listed | UBUNTU-CVE-2026-61813 |
| Ubuntu:24.04:LTS | modsecurity | no fix listed | UBUNTU-CVE-2026-61813 |
| Ubuntu:26.04:LTS | modsecurity | no fix listed | UBUNTU-CVE-2026-61813 |
| Ubuntu:26.10 | modsecurity | no fix listed | UBUNTU-CVE-2026-61813 |
| Ubuntu:26.04:LTS | modsecurity-apache | no fix listed | UBUNTU-CVE-2026-61813 |
| Ubuntu:26.10 | modsecurity-apache | no fix listed | UBUNTU-CVE-2026-61813 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| owasp-modsecurity | ModSecurity | < 2.9.15>= 3.0.0, < 3.0.17 |
Weakness: CWE-295 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
References
- https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-2vqc-36qp-ccmw x_refsource_CONFIRM
- https://github.com/owasp-modsecurity/ModSecurity/commit/cce204806430e4848327aadeb9113e654631a0c1 x_refsource_MISC
- https://github.com/owasp-modsecurity/ModSecurity/commit/edca70d853bfb725325137fa40d178beebc324fc x_refsource_MISC
- https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v2.9.15 x_refsource_MISC
- https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.17 x_refsource_MISC