Uncontrolled recursion in Coraza WAF JSON processing exhausts CPU
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- 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 3.8.0 is affected. Its JSON response body processor passes an unlimited recursion value, so the recursion is never bounded (CWE-674). A network attacker who can make an application protected by Coraza return deeply nested JSON can make response processing consume a CPU core for seconds per response, when response body inspection is enabled.
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 3.8.0, ProcessResponse in internal/bodyprocessors/json.go passes the ignoreJSONRecursionLimit value of -1 to readJSON, while the recursive guard only stops at zero. A network attacker who can cause an application protected by Coraza to return deeply nested JSON can make response-body processing perform quadratic work, consuming one CPU core for seconds per response within the default ResponseBodyLimit. Request JSON processing is not affected by this specific path because it uses the configured request recursion limit, and exploitation requires response-body inspection to be enabled. This issue is fixed in version 3.8.0.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- 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 3.8.0 | 3.8.0 | Patch available | CNA |
| — | github.com/corazawaf/coraza/v3 (Go) | 3.0.0 to before 3.8.0 | 3.8.0 | Patch available | GHSA-3c6w-j9xm-8h2h |
- coraza Vendorcorazawaf Affected 3.0.0 to before 3.8.0 Fixed in 3.8.0 Patch available CNA
- github.com/corazawaf/coraza/v3 (Go) Vendor— Affected 3.0.0 to before 3.8.0 Fixed in 3.8.0 Patch available GHSA-3c6w-j9xm-8h2h
Remediation
Version 3.8.0 of github.com/corazawaf/coraza/v3 fixes this issue. 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 3.8.0
- Fix · GHSA-3c6w-j9xm-8h2h github.com/corazawaf/coraza/v3 (Go) Fixed in 3.8.0 Advisory →
Timeline
- 2026-10-08 Threatist record created from GHSA-3c6w-j9xm-8h2h
- 2026-10-09 Alias added: CVE-2026-107833
- 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 → MEDIUM
References
More corazawaf vulnerabilities
- TI-2026-69592 Uncontrolled recursion in Coraza WAF JSON parsing crashes the process CVSS 3.1HIGH 7.5
- 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-2026-71308 CRLF injection in OWASP Coraza WAF native audit log lets attackers forge lines CVSS 3.1MEDIUM 5.8
Sources
- CVE-2026-107833 · CVE Program
- CVE-2026-107833 · NVD
- FIRST EPSS
- GHSA-3c6w-j9xm-8h2h · GitHub Advisory Database · CC BY 4.0
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