5.9

CVE-2026-107833: OWASP Coraza WAF: Unbounded recursion in JSON response body processor causes CPU exhaustion

Awaiting analysis
AliasesGHSA-3c6w-j9xm-8h2hGO-2026-6690
Published 09-10-2026Last modified 09-10-2026

Vulnerability summary

CVE-2026-107833 is a medium (CVSS 5.9) Uncontrolled Recursion vulnerability in corazawaf coraza. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 32.9% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.9, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.9/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.39%
0%100%
Low · Change unavailable
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 09-10-2026
    PublishedVulnerability first disclosed.
  2. 09-10-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.39%

Chance of exploitation in the next 30 days

Percentile

33%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

10-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Github.com/corazawaf/coraza2 products
  • v2All versions (No fix recorded)
  • v3≥ 3.0.0, < 3.8.0
Corazawaf1 product
Github.com/corazawaf1 product
  • corazaAll versions (No fix recorded)

3 vendors · 4 products

References

4 links