---
title: "CVE-2026-50886: Project Firefly III has incorrect access control in the webhook management component"
url: https://erroneo.us/security/cve/CVE-2026-50886/
description: "CVE-2026-50886 (grumpydictator/firefly-iii (Composer (PHP))): Incorrect access control in the webhook management component of Project Firefly III v6.5.9…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-06-15
date_modified: 2026-08-27
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-50886"
kev: false
cvss: 9.1
epss: 0.0044
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-50886: Project Firefly III has incorrect access control in the webhook management component

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.4% , percentile 37: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 37% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes grumpydictator/firefly-iii (Composer (PHP)) <= 6.5.9, no fixed version listed . Check your lockfile, including transitive dependencies.

## What it is

Incorrect access control in the webhook management component of Project Firefly III v6.5.9 allows attackers to scan internal resources via a crafted POST request.

## Affected packages

- Composer (PHP) `grumpydictator/firefly-iii` <= 6.5.9 → fixed: none listed

## Affected products (CVE record)

- n/a n/a: see advisory

## Severity

- CISA-ADP CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`
- GitHub CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.44% probability of exploitation activity in the next 30 days; percentile 37.

## Sources

- [GitHub Advisory GHSA-9mmg-q95p-gp67](https://github.com/advisories/GHSA-9mmg-q95p-gp67)
- [CVE.org record CVE-2026-50886](https://www.cve.org/CVERecord?id=CVE-2026-50886)
- [NVD entry CVE-2026-50886](https://nvd.nist.gov/vuln/detail/CVE-2026-50886)
- [gist.github.com](https://gist.github.com/pyuysig/f5395f90753ba652835ba9c6abf4c4ae)

---
Source page: https://erroneo.us/security/cve/CVE-2026-50886/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt