Coraza has potential denial of service vulnerability

Exploitation

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

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2023-40586: 0.72% estimated exploitation activity in the next 30 days; percentile 54.06 (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 Due to the misuse of log.Fatalf, the application using coraza crashed after receiving crafted requests from attackers. Details https://github.com/corazawaf/coraza/blob/82157f85f24c6107667bf0f686b71a72aafdf8a5/internal/bodyprocessors/multipart.go#L26-L29 The bodyprocessors of multipart uses log.Fatalf to handle errors from the mime.ParseMediaType, but log.Fatalf calls os.Exit directly after logging the error. https://github.com/golang/go/blob/a031f4ef83edc132d5f49382bfef491161de2476/src/log/log.go#L288-L291 This means that the application will immediately crash after receiving a malicious request that triggers an error in mime.ParseMediaType. PoC The server can be demonstrated by https://github.com/corazawaf/coraza/tree/main/examples/http-server After sending this request The server will crash immediately. The a=1; a=2 in Content-Type makes mime: duplicate parameter name error. Impact I believe the vulnerability was introduced by the following commit:…

Published by the source

26 Jun 2023, 15:48 UTC

Last modified by the source

10 Nov 2023, 05:04 UTC

Source last checked

26 Oct 2026, 15:00 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-c2pj-v37r-2p6h

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# Patch Next advisory brief: CVE-2023-40586

Advisory: Coraza has potential denial of service vulnerability
IDs: CVE-2023-40586, GHSA-c2pj-v37r-2p6h
Record: https://patchnext.com/advisories/cve-2023-40586 (revision 1, source checked 26 Oct 2026, 15:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
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 3.0.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/corazawaf/coraza/v3: affected >= 3.0.0, < 3.0.1; fixed in 3.0.1
- Go github.com/corazawaf/coraza/v2: affected >= 2.0.0, <= 2.0.1

## Suggested inspection (read-only)
- Go github.com/corazawaf/coraza/v3: 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/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://github.com/advisories/GHSA-c2pj-v37r-2p6h (GitHub-reviewed advisory GHSA-c2pj-v37r-2p6h lists affected ranges: Go github.com/corazawaf/coraza/v3 >=3.0.0 =2.0.0 <=2.0.1)

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