CorazaWAF Coraza up to 3.8.0 JSON Body Processor json.go readJSON stack-based overflow

Summaryinfo

A vulnerability classified as problematic was found in CorazaWAF Coraza up to 3.8.0. The affected element is the function readJSON of the file internal/bodyprocessors/json.go of the component JSON Body Processor. Such manipulation leads to stack-based overflow. This vulnerability is uniquely identified as CVE-2026-107826. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in CorazaWAF Coraza up to 3.8.0. Affected by this issue is the function readJSON of the file internal/bodyprocessors/json.go of the component JSON Body Processor. The manipulation with an unknown input leads to a stack-based overflow vulnerability. Using CWE to declare the problem leads to CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). Impacted is availability. CVE summarizes:

OWASP Coraza WAF is a golang modsecurity compatible web application firewall library. From 3.0.0 until 3.8.1, readJSON in internal/bodyprocessors/json.go can stop its bounded flattening walk after reaching SecArgumentsLimit or the byte budget and then call gjson.Valid on the complete raw body. An unauthenticated attacker can submit shallow values followed by an extremely deeply nested JSON tail that was not visited by the bounded walk, causing gjson.Valid to recurse without a depth bound and terminate the hosting process with an unrecoverable fatal stack overflow. The ProcessRequest and ProcessResponse JSON paths share the affected readJSON validation flow, and the payload can remain within recommended body-size and argument-count limits. This issue is fixed in version 3.8.1.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-107826 since 10/08/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit.

Upgrading to version 3.8.1 eliminates this vulnerability.

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Productinfo

Vendor

• CorazaWAF

Name

• Coraza

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7
• 3.8.0

Website

• Product: https://github.com/corazawaf/coraza/

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