Cyber Resilience

CVE-2026-33527

Access Control in Parseplatform Parse-Server ≤ 8.6.57

Access Control
Published
24 March 2026
Modified
25 March 2026
Patch / advisory
View advisory
CVSS Score v4 5.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/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
EPSS Score 0.0026 17th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-33527 is a medium-severity Incorrect Authorization (CWE-863) vulnerability in Parseplatform Parse-Server. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Modify Authentication Process (T1556); ranked at the 17th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability Data

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.57 and 9.6.0-alpha.48, an authenticated user can overwrite server-generated session fields such as expiresAt and createdWith when updating their…

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own session via the REST API. This allows bypassing the server's configured session lifetime policy, making a session effectively permanent. This issue has been patched in versions 8.6.57 and 9.6.0-alpha.48.

CWE(s)
CWE-863

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1556 Modify Authentication Process Defense Impairment
Adversaries may modify authentication mechanisms and processes to access user credentials or enable otherwise unwarranted access to accounts.
attack.mitre.org →
Why these techniques?

Allows authenticated user to modify session expiration fields due to missing authorization, enabling indefinite session validity and bypassing auth policy controls.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-30228Same product: Parseplatform Parse-Server
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CVE-2026-30947Same product: Parseplatform Parse-Server
CVE-2026-39381Same product: Parseplatform Parse-Server
CVE-2026-34532Same product: Parseplatform Parse-Server
CVE-2026-30965Same product: Parseplatform Parse-Server
CVE-2026-33421Same product: Parseplatform Parse-Server
CVE-2026-30854Same product: Parseplatform Parse-Server
CVE-2026-30229Same product: Parseplatform Parse-Server
CVE-2026-32742Same product: Parseplatform Parse-Server

Affected Assets

parseplatform
parse-server
9.6.0 · ≤ 8.6.57 · 9.0.0 — 9.6.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • AC-6 Least Privilege
  • SI-10 Information Input Validation
Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

AC-3 Access Enforcement good match
prevent

Directly enforces authorization policy so that users cannot modify server-controlled session attributes (expiresAt, createdWith) during REST updates.

AC-6 Least Privilege good match
prevent

Ensures authenticated users receive only the minimum privileges required, preventing them from overwriting protected session metadata fields.

SI-10 Information Input Validation partial match
prevent

Validates incoming session-update payloads and rejects any attempt to supply or alter server-generated fields.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 mostly match
prevents

Defining, enforcing, and reviewing access authorizations and least privilege directly prevents incorrect authorization checks.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.15 Access control partial match
prevents

Requiring consistency between access rights and classification plus formal approval steps ensures that the authorization logic correctly distinguishes between entities that should and should not be granted access.

A.5.18 Access rights partial match
prevents

Enforcing policy-driven approval and role-change reviews stops incorrect or stale authorization decisions from remaining in effect after job changes or terminations.

A.8.3 Information access restriction partial match
prevents

By tying access rights to identity, device, location and classification, the control reduces the likelihood that an authorization decision will be based on an incorrect or bypassed policy.

References