Uncontrolled recursion in Coraza WAF JSON parsing crashes the process
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-674.
Summary
OWASP Coraza WAF from 3.0.0 before 3.8.1 is affected. Its JSON body processor can stop a bounded walk early and then validate the full body with recursion that has no depth limit (CWE-674). An unauthenticated remote attacker can send a deeply nested JSON body within common size and argument limits, causing a fatal stack overflow that terminates the hosting process.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| corazawaf | coraza | 3.0.0 to before 3.8.1 | 3.8.1 | Patch available | CNA |
| — | github.com/corazawaf/coraza/v3 (Go) | 3.0.0 to before 3.8.1 | 3.8.1 | Patch available | GHSA-6gcq-wc29-5xf2 |
- coraza Vendorcorazawaf Affected 3.0.0 to before 3.8.1 Fixed in 3.8.1 Patch available CNA
- github.com/corazawaf/coraza/v3 (Go) Vendor— Affected 3.0.0 to before 3.8.1 Fixed in 3.8.1 Patch available GHSA-6gcq-wc29-5xf2
Remediation
The Go module github.com/corazawaf/coraza/v3 is fixed in version 3.8.1. The sources list no fixed version for coraza.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
- Fix · CNA coraza (corazawaf) Fixed in 3.8.1
- Fix · GHSA-6gcq-wc29-5xf2 github.com/corazawaf/coraza/v3 (Go) Fixed in 3.8.1 Advisory →
Timeline
- 2026-10-08 Threatist record created from GHSA-6gcq-wc29-5xf2
- 2026-10-09 Alias added: CVE-2026-107826
- 2026-10-10 Title updated · CNA
- 2026-10-10 CVSS score added · CNA
- 2026-10-10 Weakness changed · CNA
- 2026-10-10 Affected versions changed · CNA
- 2026-10-10 3 new references · CNA
- 2026-10-10 CISA SSVC decision points changed
- 2026-10-10 Priority changed: LOW → HIGH
References
More corazawaf vulnerabilities
- TI-2026-71270 Coraza WAF silently drops arguments at ArgumentLimit, enabling rule bypass CVSS 3.1HIGH 7.2
- TI-2026-71268 Off-by-one error in OWASP Coraza jsDecode enables WAF rule bypass CVSS 3.1MEDIUM 5.8
- TI-2026-78712 Coraza JSON key collision lets SQL injection evade WAF rules CVSS 4.0MEDIUM 6.9
- TI-2026-78714 Multipart filename* charset handling bypasses Coraza FILES rules CVSS 4.0MEDIUM 6.3
- TI-2026-69596 Uncontrolled recursion in Coraza WAF JSON processing exhausts CPU CVSS 3.1MEDIUM 5.9
- TI-2026-71308 CRLF injection in OWASP Coraza WAF native audit log lets attackers forge lines CVSS 3.1MEDIUM 5.8
Sources
- CVE-2026-107826 · CVE Program
- CVE-2026-107826 · NVD
- FIRST EPSS
- GHSA-6gcq-wc29-5xf2 · GitHub Advisory Database · CC BY 4.0
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