Coraza: URL-encoded form Content-Type parameters bypass Coraza body inspection

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

EPSS

• CVE-2026-114100: 0.28% estimated exploitation activity in the next 30 days; percentile 20.81 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Coraza fails to inspect URL-encoded form bodies when their valid Content-Type contains a media-type parameter, for example: An unauthenticated attacker can use this header to hide the complete form body from custom Coraza rules that inspect ARGSPOST or REQUESTBODY, while the bundled Go HTTP middleware forwards the body and the backend parses it normally. This is a deterministic request-body inspection bypass. Suggested severity: Medium. Current OWASP CRS includes rule 901340, which forces fallback inspection and mitigates this path; this report does not claim a bypass of an unmodified current CRS ruleset Details The affected component is request-body processor selection in internal/corazawaf/transaction.go. Transaction.AddRequestHeader compares the complete lowercased header value using exact equality: Source: internal/corazawaf/transaction.go, lines 383-390. The media type of application/x-www-form-urlencoded; charset=UTF-8 remains application/x-www-form-urlencoded; charset…

Published by the source

8 Oct 2026, 17:51 UTC

Last modified by the source

21 Oct 2026, 10:56 UTC

Source last checked

26 Oct 2026, 15:32 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-w253-m66g-rx24

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6698

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-w253-m66g-rx24

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# Patch Next advisory brief: CVE-2026-114100

Advisory: Coraza: URL-encoded form Content-Type parameters bypass Coraza body inspection
IDs: CVE-2026-114100, GHSA-w253-m66g-rx24
Record: https://patchnext.com/advisories/cve-2026-114100 (revision 3, source checked 26 Oct 2026, 15:32 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: github.com/corazawaf/coraza/v3 3.8.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/corazawaf/coraza/v3: affected >= 3.0.4, < 3.8.1; fixed in 3.8.1
- Go github.com/corazawaf/coraza: affected every version
- Go github.com/corazawaf/coraza/v2: affected every version

## Suggested inspection (read-only)
- Go github.com/corazawaf/coraza/v3: check the installed version with your package manager.
- Go github.com/corazawaf/coraza: check the installed version with your package manager.
- Go github.com/corazawaf/coraza/v2: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/corazawaf/coraza/v3, github.com/corazawaf/coraza, github.com/corazawaf/coraza/v2.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GO-2026-6698 (OSV record GO-2026-6698 lists affected ranges: Go github.com/corazawaf/coraza >=0; Go github.com/corazawaf/coraza/v2 >=0; Go github.com/corazawaf/coraza/v3 >=3.0.4 <3.8.1 (fixed))
- Verified: https://osv.dev/vulnerability/GHSA-w253-m66g-rx24 (OSV record GHSA-w253-m66g-rx24 lists affected ranges: Go github.com/corazawaf/coraza/v3 >=3.0.4 <3.8.1 (fixed))
- Verified: https://github.com/advisories/GHSA-w253-m66g-rx24 (GitHub-reviewed advisory GHSA-w253-m66g-rx24 lists affected ranges: Go github.com/corazawaf/coraza/v3 >=3.0.4 <3.8.1)

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