Vulnerability in Corazawaf Coraza

CVE-2026-107826

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.

Published .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-107826?
CVE-2026-107826 is a high-severity vulnerability in Corazawaf Coraza, classified under Uncontrolled Recursion. CVSS score: 7.5/10. Published 2026-10-09.
How severe is CVE-2026-107826?
High severity. CVSS v3 base score is 7.5 out of 10.