{"id":"CVE-2026-107826","revision":null,"records":[{"revision":"cf1a00408b7f40e9ae7bc6814bb72abb","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-107826","aliases":[],"title":"OWASP Coraza WAF: JSON body processor: argument-limit truncation reopens an unbounded-depth gjson.Valid stack overflow (process crash)","description":"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.","state":0,"publishedAt":"2026-10-09T17:33:49.389+00:00","modifiedAt":"2026-10-09T17:55:14.751+00:00","affected":[{"ecosystem":"Vendor product","name":"coraza","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"corazawaf\",\n                    \"product\": \"coraza\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 3.0.0, < 3.8.1\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://github.com/corazawaf/coraza/security/advisories/GHSA-6gcq-wc29-5xf2","https://github.com/corazawaf/coraza/commit/814e1898e083d2ff2ceb644382d0da17e930f93f","https://github.com/corazawaf/coraza/releases/tag/v3.8.1"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-107826","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-107826","identifiers":["CVE-2026-107826"]},"retained":false,"historicalAffected":[]},{"revision":"75c6ec5beb884259bf3d960bc396725e","observedAt":"2026-11-07T04:31:41.853+00:00","statement":{"source":"euvd","id":"EUVD-2026-95925","aliases":["CVE-2026-107826"],"title":"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 budg…","description":"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.","state":0,"publishedAt":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":null}],"references":["https://github.com/corazawaf/coraza/security/advisories/GHSA-6gcq-wc29-5xf2","https://github.com/corazawaf/coraza/commit/814e1898e083d2ff2ceb644382d0da17e930f93f","https://github.com/corazawaf/coraza/releases/tag/v3.8.1"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-95925","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"Oct 9, 2026, 5:33:49 PM","dateUpdated":"Oct 9, 2026, 5:55:14 PM"},"relatedAdvisories":[],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2026-95925","identifiers":["EUVD-2026-95925","CVE-2026-107826"]},"retained":false,"historicalAffected":[]},{"revision":"d9267e39b61b4a2eb14d7fc71bab71aa","observedAt":"2026-10-25T05:17:13.11+00:00","statement":{"source":"nvd","id":"CVE-2026-107826","aliases":[],"title":"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 budg…","description":"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.","state":0,"publishedAt":"2026-10-09T18:17:04.673+00:00","modifiedAt":"2026-10-16T17:16:41.3+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · security-advisories@github.com · Secondary","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://github.com/corazawaf/coraza/commit/814e1898e083d2ff2ceb644382d0da17e930f93f","https://github.com/corazawaf/coraza/releases/tag/v3.8.1","https://github.com/corazawaf/coraza/security/advisories/GHSA-6gcq-wc29-5xf2"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-107826","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Awaiting Analysis","weaknesses":["CWE-674"],"productCriteria":[],"sourceDates":{"published":"2026-10-09T18:17:04.673","lastModified":"2026-10-16T17:16:41.300"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-107826","identifiers":["CVE-2026-107826"]},"retained":false,"historicalAffected":[]},{"revision":"1bf8383ad42b41c49f419631a623e09d","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-6gcq-wc29-5xf2","aliases":["CVE-2026-107826","GO-2026-6693"],"title":"Coraza JSON body processor: argument-limit truncation reopens an unbounded-depth gjson.Valid stack overflow (process crash)","description":"### Summary\n\nThe JSON body processor (`internal/bodyprocessors/json.go`) can be made to\ncrash the whole process with an unrecoverable `fatal error: stack overflow`,\nusing a request body that is well under the recommended `SecRequestBodyLimit`\nand the default `SecArgumentsLimit`.\n\n### Root cause\n\n`readJSON` (json.go:113-143) runs a bounded, best-effort flattening walk\n(`readItems`) and *afterwards* calls `gjson.Valid(s)` on the raw body if\n`readItems` returned no error:\n\n```go\njson := gjson.Parse(s)\n...\ntruncated, err = readItems(json, key, maxRecursion, argumentLimit, byteBudget, &usedBytes, &argCount, res)\nif err != nil {\n    return res, truncated, err\n}\nif !gjson.Valid(s) {\n    return res, truncated, errors.New(\"invalid JSON\")\n}\n```\n\n`gjson.Valid` (gjson v1.18.0, `validany` -> `validarray`/`validobject`) recurses\nonce per nesting level with **no depth bound**. `readItems` does have a depth\nbound (`maxRecursion`), enforced here (json.go:163-182):\n\n```go\nfunc readItems(json gjson.Result, objKey []byte, maxRecursion int, argumentLimit int, byteBudget int, usedBytes *int, argCount *int, res map[string][]string) (truncated bool, err error) {\n    if byteBudget > 0 && *usedBytes >= byteBudget {\n        return true, nil                 // <-- checked first\n    }\n    if argumentLimit > 0 && *argCount >= argumentLimit {\n        return true, nil                 // <-- checked second\n    }\n    ...\n    if maxRecursion <= 0 {\n        return false, errors.New(\"max recursion reached while reading json object\")\n    }\n```\n\nThe byte-budget and argument-limit checks run *before* the recursion-depth\ncheck, and they short-circuit the walk with `truncated=true, err=nil` instead\nof recursing further. If the configured `SecArgumentsLimit`\n(`ArgumentLimit`, default 1000, `internal/corazawaf/waf.go:359`) is reached by\nearlier, shallow values in the document, `readItems` stops walking *before it\never reaches* a deeply nested tail later in the same document — so the\n`maxRecursion` error is never produced, `err` comes back `nil`, and `readJSON`\nfalls through to the unconditional `gjson.Valid(s)` call on the complete raw\nbody, including the part `readItems` never visited.\n\nThis is not a new interaction with the recursion limit itself: at v3.7.0,\n`gjson.Valid` ran unconditionally before any recursion check at all, so a\nplain deeply-nested body crashed the process directly. A later fix added a\ndepth check that returns an error before `Valid` runs for the *straightforward*\ncase (nesting reached before any other guard fires). The argument-limit /\nbyte-budget guards added since then (GHSA-6r3q-mjv7-xr8m,\nGHSA-3ww9-vw83-9w5x) reopened the same crash for the case above, because they\nshort-circuit the walk (and therefore the recursion counter) ahead of the\ndepth check, on both the request and response body path (`ProcessResponse`\ncalls the same `readJSON`, json.go:57-88).\n\nBecause this is `fatal error: stack overflow`, not a `panic`, it is **not**\nrecoverable by any `recover()` in the calling goroutine — the process\nterminates unconditionally.\n\n### PoC\n\n```go\npackage bodyprocessors\n\nimport (\n    \"strings\"\n    \"testing\"\n)\n\nfunc TestStackOverflowRepro(t *testing.T) {\n    body := \"[\" + strings.Repeat(\"1,\", 1000) + strings.Repeat(\"[\", 13_000_000)\n    // 13,002,001 bytes total: under the recommended SecRequestBodyLimit\n    // (13107200, coraza.conf-recommended:78) and default ArgumentLimit (1000,\n    // internal/corazawaf/waf.go:359).\n    _, _, _ = readJSON(body, 20, 1000)\n}\n```\n\n```\n$ go test -run TestStackOverflowRepro ./internal/bodyprocessors/ -v\nruntime: goroutine stack exceeds 1000000000-byte limit\nfatal error: stack overflow\n...\ngithub.com/tidwall/gjson.validarray(...)\n\t.../gjson@v1.18.0/gjson.go:2584\ngithub.com/tidwall/gjson.validany(...)\n\t.../gjson@v1.18.0/gjson.go:2499\ngithub.com/tidwall/gjson.validarray(...)\n\t.../gjson@v1.18.0/gjson.go:2589\n... (repeats until the goroutine stack limit is hit)\n```\n\nReproduced against commit `19b86824` (tag `v3.8.0`), both by calling\n`readJSON` directly and end-to-end through the recommended\n`coraza.conf-recommended` configuration (JSON `Content-Type`, default\n`SecArgumentsLimit`, recommended `SecRequestBodyLimit`).\n\n### Impact\n\nAn unauthenticated attacker who can send an HTTP request body (any endpoint\nprotected by Coraza with the JSON body processor enabled, which is the\ndefault for `application/json`) can crash the entire host process with a\nsingle request, using a payload well within default and recommended body\nsize and argument-count limits. There is no privilege or interaction\nrequirement, and the crash cannot be caught or mitigated by the integrator\n(no `recover()` stops a stack-overflow fatal error). This is strictly worse\nthan a CPU-exhaustion or slow-request DoS: the process must be restarted, and\nevery in-flight request/transaction on that process is lost.\n\n### Suggested fix\n\nRun an iterative, explicitly-bounded-depth pre-scan (or reuse `readItems`'s\nown recursion accounting) before calling `gjson.Valid`, and never call\n`gjson.Valid` on input whose nesting exceeds `maxRecursion`. The response\npath (`ProcessResponse`) needs the same treatment since it shares `readJSON`.\n\n### AI involvement disclosure\n\n- **AI tools/models used:** Claude Sonnet 5 (Anthropic), via Claude Code.\n- **What was generated/assisted:** the initial vulnerability hypothesis and\n  repro shape were supplied by the reporter as an existing written finding;\n  Claude Sonnet 5 independently re-derived the root cause by reading the\n  current source, wrote and ran a fresh PoC test against commit `19b86824`\n  (tag `v3.8.0`), confirmed the crash and stack trace shown above, verified\n  the default configuration values cited (`ArgumentLimit` default,\n  `SecRequestBodyLimit` recommended value) against the current source, and\n  drafted this advisory text.\n- **Review performed:** reproduced by hand by running the PoC test above with\n  `go test -run TestStackOverflowRepro ./internal/bodyprocessors/ -v` against\n  a clean checkout of commit `19b86824`; observed the `fatal error: stack\n  overflow` and stack trace through `gjson.validarray`/`validany`; traced\n  `readJSON`/`readItems` line by line to confirm the guard ordering described\n  above; the PoC was reviewed by a human maintainer (fzipi) before\n  submission of this advisory.","state":0,"publishedAt":"2026-10-08T17:45:46+00:00","modifiedAt":"2026-10-19T21:40:44.3888181+00:00","affected":[{"ecosystem":"Go","name":"github.com/corazawaf/coraza/v3","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"3.0.0"},{"kind":"fixed","version":"3.8.1"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"HIGH"}],"references":["https://github.com/corazawaf/coraza/security/advisories/GHSA-6gcq-wc29-5xf2","https://github.com/corazawaf/coraza/commit/814e1898e083d2ff2ceb644382d0da17e930f93f","https://github.com/corazawaf/coraza","https://github.com/corazawaf/coraza/releases/tag/v3.8.1"],"sourceUrl":"https://github.com/advisories/GHSA-6gcq-wc29-5xf2","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-6gcq-wc29-5xf2","identifiers":["GHSA-6gcq-wc29-5xf2","CVE-2026-107826","GO-2026-6693"]},"retained":false,"historicalAffected":[]},{"revision":"450e1fb824e9481dbb05be7ca1808b62","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GO-2026-6693","aliases":["CVE-2026-107826","GHSA-6gcq-wc29-5xf2"],"title":"Coraza JSON body processor: argument-limit truncation reopens an unbounded-depth gjson.Valid stack overflow (process crash) in github.com/corazawaf/coraza","description":"Coraza JSON body processor: argument-limit truncation reopens an unbounded-depth gjson.Valid stack overflow (process crash) in github.com/corazawaf/coraza","state":0,"publishedAt":"2026-10-19T21:08:17+00:00","modifiedAt":"2026-10-19T21:40:44.3888181+00:00","affected":[{"ecosystem":"Go","name":"github.com/corazawaf/coraza","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"Go","name":"github.com/corazawaf/coraza/v2","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"Go","name":"github.com/corazawaf/coraza/v3","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"3.0.0"},{"kind":"fixed","version":"3.8.1"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[],"references":["https://github.com/corazawaf/coraza/security/advisories/GHSA-6gcq-wc29-5xf2","https://github.com/corazawaf/coraza/commit/814e1898e083d2ff2ceb644382d0da17e930f93f","https://github.com/corazawaf/coraza/releases/tag/v3.8.1"],"sourceUrl":"https://osv.dev/vulnerability/GO-2026-6693","license":"OSV · upstream source license applies","key":"osv:GO-2026-6693","identifiers":["GO-2026-6693","CVE-2026-107826","GHSA-6gcq-wc29-5xf2"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. 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