---
title: "CVE-2026-30965: Parse Server vulnerable to session token exfiltration via `redirectClassNameForKey` query parameter"
url: https://erroneo.us/security/cve/CVE-2026-30965/
description: "CVE-2026-30965 (parse-server (npm)): Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-03-10
date_modified: 2026-03-11
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-30965"
kev: false
cvss: 9.9
epss: 0.01555
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-30965: Parse Server vulnerable to session token exfiltration via `redirectClassNameForKey` query parameter

**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?

- 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 1.6% , percentile 75: FIRST’s model estimates a 1.6% chance of exploitation activity in the next 30 days, higher than 75% of all scored CVEs (moderate). 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 parse-server (npm) >= 9.0.0-alpha.1, < 9.5.2-alpha.8, fixed in 9.5.2-alpha.8 ; parse-server (npm) < 8.6.21, fixed in 8.6.21 . Check your lockfile, including transitive dependencies.

## What it is

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.5.2-alpha.8 and 8.6.21, a vulnerability in Parse Server's query handling allows an authenticated or unauthenticated attacker to exfiltrate session tokens of other users by exploiting the redirectClassNameForKey query parameter. Exfiltrated session tokens can be used to take over user accounts. The vulnerability requires the attacker to be able to create or update an object with a new relation field, which depends on the Class-Level Permissions of at least one class. This vulnerability is fixed in 9.5.2-alpha.8 and 8.6.21.

## Affected packages

- npm `parse-server` >= 9.0.0-alpha.1, < 9.5.2-alpha.8 → fixed: 9.5.2-alpha.8
- npm `parse-server` < 8.6.21 → fixed: 8.6.21

## Affected products (CVE record)

- parse-community parse-server: >= 9.0.0 < 9.5.2-alpha.8, < 8.6.21

## Severity

- GitHub_M CVSS 4.0: 9.9 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N`
- GitHub CVSS 4.0: 9.9 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N`

## 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): 1.55% probability of exploitation activity in the next 30 days; percentile 75.

## Sources

- [GitHub Advisory GHSA-6r2j-cxgf-495f](https://github.com/advisories/GHSA-6r2j-cxgf-495f)
- [CVE.org record CVE-2026-30965](https://www.cve.org/CVERecord?id=CVE-2026-30965)
- [NVD entry CVE-2026-30965](https://nvd.nist.gov/vuln/detail/CVE-2026-30965)
- [github.com](https://github.com/parse-community/parse-server/security/advisories/GHSA-6r2j-cxgf-495f)
- [github.com](https://github.com/parse-community/parse-server/releases/tag/8.6.21)
- [github.com](https://github.com/parse-community/parse-server/releases/tag/9.5.2-alpha.8)

---
Source page: https://erroneo.us/security/cve/CVE-2026-30965/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt