---
title: "CVE-2026-39087: ntfy.sh allows a remote attacker to execute arbitrary code via the parseActions function"
url: https://erroneo.us/security/cve/CVE-2026-39087/
description: "CVE-2026-39087 (heckel.io/ntfy/v2 (Go)): ntfy before 2.22.0 allows SSRF because of an unanchored regular expression for web push endpoint URLs."
type: vulnerability-record
section: "Security Digest"
date_published: 2026-04-23
date_modified: 2026-07-05
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-39087"
kev: false
cvss: 6.4
epss: 0.00482
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-39087: ntfy.sh allows a remote attacker to execute arbitrary code via the parseActions function

**Signal:** Normal patch cycle. No exploitation signal; fix it in your next routine update if you are affected. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.5% , percentile 41: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 41% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes heckel.io/ntfy/v2 (Go) < 2.22.0, fixed in 2.22.0 . Check your lockfile, including transitive dependencies.

## What it is

ntfy before 2.22.0 allows SSRF because of an unanchored regular expression for web push endpoint URLs.

## Affected packages

- Go `heckel.io/ntfy/v2` < 2.22.0 → fixed: 2.22.0

## Affected products (CVE record)

- ntfy ntfy: < 2.22.0

## Severity

- mitre CVSS 3.1: 6.4 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N`
- CISA-ADP CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.48% probability of exploitation activity in the next 30 days; percentile 41.

## Sources

- [GitHub Advisory GHSA-pqhx-w72w-m393](https://github.com/advisories/GHSA-pqhx-w72w-m393)
- [CVE.org record CVE-2026-39087](https://www.cve.org/CVERecord?id=CVE-2026-39087)
- [NVD entry CVE-2026-39087](https://nvd.nist.gov/vuln/detail/CVE-2026-39087)
- [gist.github.com](https://gist.github.com/MightyNawaf/5d41d6e8ead16e217f86b016002ecae5)
- [github.com](https://github.com/binwiederhier/ntfy/releases/tag/v2.22.0)
- [ntfy.sh](https://ntfy.sh)
- [ntfy.com](http://ntfy.com)
- [ntfysh.com](http://ntfysh.com)

---
Source page: https://erroneo.us/security/cve/CVE-2026-39087/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt