# CVE-2026-91080: webhook through 2.8.3 Memory Exhaustion via Oversized Request Body

> Unauthenticated attackers can crash the webhook service by sending oversized request bodies, causing memory exhaustion.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Sep 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-4wr8-3xfv-vhj5

## What is CVE-2026-91080?

CVE-2026-91080 is a high-severity denial of service vulnerability in adnanh webhook, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

webhook through 2.8.3 reads the entire request body into memory before evaluating trigger rules, allowing unauthenticated attackers to exhaust memory by sending oversized bodies. Attackers can send multi-gigabyte request bodies with invalid signatures to trigger out-of-memory conditions and crash the service.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-91080?


## How do I fix CVE-2026-91080?

No fix has been published for CVE-2026-91080 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-91080 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-91080 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-91080 and fix it if it is affected.

What it is: CVE-2026-91080 is a high-severity denial of service vulnerability in adnanh webhook, published on 14 Sep 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-2026-91080 exists.

Affected product: adnanh webhook. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-91080/ (Markdown: https://insights.sbomify.com/CVE-2026-91080/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-91080
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-91080
- OSV: https://osv.dev/vulnerability/CVE-2026-91080

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-91080/
Summaries are generated and may contain mistakes; the official description above is the record.