CVE-2026-30965 — parse-server
CVE-2026-30965 is a CWE-863 vulnerability in parse-server. A fix is available for parse-server — see the affected versions and patch details below.
Parse Server session token exfiltration via `redirectClassNameForKey` query parameter
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-30965.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
parse-servernpmDescription
Impact
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.
Patches
The fix applies the same security checks that normally protect class access after the query redirect, ensuring that queries redirected via redirectClassNameForKey are subject to the same restrictions as direct queries to the target class.
Workarounds
Set restrictive Class-Level Permissions to prevent clients from creating new fields on classes, specifically by disabling addField for public access and unauthenticated users. Note that this limits client functionality and does not fully eliminate the risk if a relation field pointing to a protected class already exists in the schema.
References
- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-6r2j-cxgf-495f
- Fix Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.5.2-alpha.8
- Fix Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.21
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | parse-server | ≥ 9.0.0-alpha.1&&< 9.5.2-alpha.8 | 9.5.2-alpha.8npm install parse-server@9.5.2-alpha.8 |
| 📦npm | parse-server | all versions | 8.6.21npm install parse-server@8.6.21 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for parse-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update parse-server to 9.5.2-alpha.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-30965 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-30965 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-30965. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect CVE-2026-30965
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2026-30965 -u https://target- Template
- Parse Server < 8.6.21 / 9.x < 9.5.2 - Session Token Exfiltration
- Severity
- critical
- Impact
- Attackers can exfiltrate session tokens and take over user accounts, leading to account compromise.
- Remediation
- Update to version 9.5.2-alpha.8 or 8.6.21 or later.
Template by ProjectDiscovery nuclei-templates (str4k3r, 0x_Akoko), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2026-30965 in your dependencies?
O3 Security finds CVE-2026-30965 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.