# CVE-2026-107835: OWASP Coraza WAF: Cookie Parser Confusion

> An attacker can bypass WAF rules by crafting cookie headers that are parsed differently by Coraza and the backend application.

- **Severity:** Medium 4.0 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Oct 2026
- **Updated:** 9 Oct 2026
- **Also known as:** GHSA-g4qm-m288-5cp9, GO-2026-6694

## What is CVE-2026-107835?

CVE-2026-107835 is a medium-severity vulnerability in corazawaf coraza, published on 9 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

OWASP Coraza WAF is a golang modsecurity compatible web application firewall library. Prior to 3.8.1, internal/cookies.ParseCookies in internal/cookies/cookies.go handles boundary ASCII control characters and control-only or empty cookie names differently from several backend cookie parsers. An unauthenticated attacker can craft a Cookie header so Coraza indexes or drops a cookie under a different name or value from the backend application, causing rules targeting REQUEST_COOKIES or REQUEST_COOKIES_NAMES to miss application-visible attacker data. Exploitation depends on the backend parser and affected rule scope, and interior control characters with inconsistent backend behavior are outside this advisory's remediation. This issue is fixed in version 3.8.1.

Weakness: CWE-436 (Interpretation Conflict)

## Which versions are affected by CVE-2026-107835?

5 open source packages ship an affected version, including github.com/corazawaf/coraza/v3, github.com/corazawaf/coraza and github.com/corazawaf/coraza/v2.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/corazawaf/coraza/v3` | Go | All versions | 3.8.1 |
| `github.com/corazawaf/coraza/v3` | Go | All versions | 3.8.1 |
| `github.com/corazawaf/coraza/v3` | Go | All versions | 3.8.1 |
| `github.com/corazawaf/coraza` | Go | All versions | None |
| `github.com/corazawaf/coraza/v2` | Go | All versions | None |

## How do I fix CVE-2026-107835?

Upgrade github.com/corazawaf/coraza/v3 to 3.8.1 or later.

## Is CVE-2026-107835 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-107835 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-107835 and fix it if it is affected.

What it is: CVE-2026-107835 is a medium-severity vulnerability in corazawaf coraza, published on 9 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-107835 exists.

Affected packages and fixed versions:
- github.com/corazawaf/coraza/v3 (Go): affected all versions; fixed in 3.8.1
- github.com/corazawaf/coraza/v3 (Go): affected all versions; fixed in 3.8.1
- github.com/corazawaf/coraza/v3 (Go): affected all versions; fixed in 3.8.1
- github.com/corazawaf/coraza (Go): affected all versions; no fix listed
- github.com/corazawaf/coraza/v2 (Go): affected all versions; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-107835/ (Markdown: https://insights.sbomify.com/CVE-2026-107835/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-107835
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-107835
- OSV: https://osv.dev/vulnerability/CVE-2026-107835

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-107835/
Summaries are generated and may contain mistakes; the official description above is the record.