Parse Server: Endpoint `/loginAs` allows `readOnlyMasterKey` to gain full read and write access as any user
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.6 and 9.5.0-alpha.4, the readOnlyMasterKey can call POST /loginAs to obtain a valid session token for any user. This allows a read-only credential to impersonate arbitrary users with full read and write access to their data. Any Parse Server deployment that uses readOnlyMasterKey is affected. This issue has been patched in versions 8.6.6 and 9.5.0-alpha.4.
- Published
- Mar 6, 2026
- Updated
- Jun 17, 2026
- EPSS
- 0.6% · 44th percentile
- CWE
- CWE-863
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Report tools
Action score
34
Monitor
Low priority for now.
- CVSS
- 34 / 40 · 8.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.6%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 8.5
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| parseplatform | parse-server | cpe:2.3:a:parseplatform:parse-server |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- parseplatform parse-serverbefore 8.6.6
- parseplatform parse-server9.0.0 and later · up to 9.4.1 inclusive
- parseplatform parse-server9.5.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
parse-community parse-server
- < 8.6.6, < 9.5.0-alpha.4affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| npm | parse-server | from 9.0.0 · before 9.5.0-alpha.4 | 9.5.0-alpha.4 |
| npm | parse-server | before 8.6.6 | 8.6.6 |
Same product
parseplatform: all recordsOther highest-scoring records for the same primary product.
- CVE-2022-24760Command Injection in Parse server55Plan
- CVE-2022-39396Parse Server vulnerable to Remote Code Execution via prototype pollution in MongoDB BSON parser51Plan
- CVE-2026-30966Parse Server role escalation and CLP bypass via direct `_Join` table write40Plan
- CVE-2024-27298Parse Server literalizeRegexPart SQL Injection40Plan
- CVE-2023-36475Parse Server vulnerable to remote code execution via MongoDB BSON parser through prototype pollution40Plan
- CVE-2026-30965Parse Server session token exfiltration via `redirectClassNameForKey` query parameter39Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| npm:parse-server | 8.6.6 | Package registry (OSV) |
| npm:parse-server | 9.5.0-alpha.4 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-309654 days apartParse Server session token exfiltration via `redirectClassNameForKey` query parameter39Monitor
- CVE-2026-3453225 days apartParse Server: Cloud function validator bypass via prototype chain traversal36Monitor
- CVE-2026-291820 days apartParse Server: Cloud Hooks and Cloud Jobs bypass `readOnlyMasterKey` write restriction34Monitor
- CVE-2026-309474 days apartParse Server ha a bypass of class-level permissions in LiveQuery34Monitor
- CVE-2026-3342118 days apartParse Server: LiveQuery bypasses CLP pointer permission enforcement28Monitor
- CVE-2026-302280 days apartParse Server: File creation and deletion bypasses `readOnlyMasterKey` write restriction27Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- Administrator privileges are required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- High
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-863 · Incorrect AuthorizationCVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/parse-community/parse-server/releases/tag/8.6.6
- github.com/parse-community/parse-server/releases/tag/9.5.0-alpha.4
- github.com/parse-community/parse-server/security/advisories/GHSA-79wj-8rqv-jvp5
Vendor advisories and official records. Exploit/PoC links are deliberately left out.