# CVE-2026-101049: Heym before 0.0.53 Slack Webhook Signature Verification Bypass

> Remote attackers can bypass Slack signature verification to trigger workflows with owner credentials when signing secrets are missing or empty.

- **Severity:** High 8.3 (`CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/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:** 27 Sep 2026
- **Updated:** 28 Sep 2026
- **Also known as:** GHSA-2m9j-ffq7-cjqc

## What is CVE-2026-101049?

CVE-2026-101049 is a high-severity authentication bypass vulnerability in heymrun heym, published on 27 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Heym before 0.0.53 fails to verify Slack request signatures when trigger nodes lack credential IDs or have empty signing secrets. Remote unauthenticated attackers can send forged Slack events to known webhook URLs to trigger workflows with the owner's credentials.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-101049?


## How do I fix CVE-2026-101049?

No fix has been published for CVE-2026-101049 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-101049 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-101049 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-101049 and fix it if it is affected.

What it is: CVE-2026-101049 is a high-severity authentication bypass vulnerability in heymrun heym, published on 27 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-2026-101049 exists.

Affected product: heymrun heym. 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-2026-101049/ (Markdown: https://insights.sbomify.com/CVE-2026-101049/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-101049
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-101049
- OSV: https://osv.dev/vulnerability/CVE-2026-101049

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-101049/
Summaries are generated and may contain mistakes; the official description above is the record.