Cyber Resilience

CVE-2026-34373

Parseplatform Parse-Server 3.5.0 – 8.6.66

Published
31 March 2026
Modified
24 July 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:N/UI:P/VC:N/VI:N/VA:N/SC:L/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 0.0020 10th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-34373 is a medium-severity Origin Validation Error (CWE-346) vulnerability in Parseplatform Parse-Server. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique DHCP Spoofing (T1557.003); ranked at the 10th 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-4 (Information Flow Enforcement) and IA-3 (Device Identification and Authentication) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-34373 is a vulnerability in Parse Server, an open-source backend platform deployable on any Node.js-compatible infrastructure. In versions prior to 8.6.66 and 9.7.0-alpha.10, the GraphQL API endpoint ignores the configured allowOrigin server option, allowing cross-origin requests from any website. This bypasses restrictions operators set to limit which websites can interact with the Parse Server API, while the REST API correctly enforces these origin controls. The flaw carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) and is associated with CWE-346 (Origin Validation Error).

Any remote attacker can exploit this vulnerability by tricking users into visiting a malicious website that issues unauthorized cross-origin GraphQL requests to the affected Parse Server instance. Exploitation requires user interaction, such as loading the site or clicking an element, but demands no privileges or authentication. Successful attacks enable high-impact effects, including unauthorized access to sensitive data (confidentiality), modification of server resources (integrity), and potential service disruption (availability), all scoped to the unchanged security context.

Parse Server maintainers have patched the issue in versions 8.6.66 and 9.7.0-alpha.10. Security advisories recommend immediate upgrades to these releases to restore proper enforcement of allowOrigin restrictions on the GraphQL endpoint. Details on the fixes are documented in the GitHub security advisory (GHSA-q3p6-g7c4-829c) and related pull requests (#10334, #10335) with commits (0347641507891d0013ec57f7c10f012064f41263, 4dd0d3d8be1c39664c74ad10bb0abaa76bc41203).

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

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 8.6.66 and 9.7.0-alpha.10, the GraphQL API endpoint does not respect the allowOrigin server option and unconditionally allows cross-origin requests…

more

from any website. This bypasses origin restrictions that operators configure to control which websites can interact with the Parse Server API. The REST API correctly enforces the configured allowOrigin restriction. This issue has been patched in versions 8.6.66 and 9.7.0-alpha.10.

CWE(s)
CWE-346

Related Threats

MITRE ATT&CK Enterprise Techniques

T1557.003 DHCP Spoofing Credential Access
Adversaries may redirect network traffic to adversary-owned systems by spoofing Dynamic Host Configuration Protocol (DHCP) traffic and acting as a malicious DHCP server on the victim network.
attack.mitre.org →
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
attack.mitre.org →
T1557.001 Name Resolution Poisoning and SMB Relay Credential Access
By responding to LLMNR/NBT-NS/mDNS network traffic, adversaries may spoof an authoritative source for name resolution to force communication with an adversary controlled system.
attack.mitre.org →
T1557.002 ARP Cache Poisoning Credential Access
Adversaries may poison Address Resolution Protocol (ARP) caches to position themselves between the communication of two or more networked devices.
attack.mitre.org →
T1557.004 Evil Twin Credential Access
Adversaries may host seemingly genuine Wi-Fi access points to deceive users into connecting to malicious networks as a way of supporting follow-on behaviors such as [Network Sniffing](https://attack.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-22474Same product: Parseplatform Parse-Server
CVE-2026-35200Same product: Parseplatform Parse-Server
CVE-2026-33409Same product: Parseplatform Parse-Server
CVE-2026-30949Same product: Parseplatform Parse-Server
CVE-2026-30967Same product: Parseplatform Parse-Server
CVE-2026-33042Same product: Parseplatform Parse-Server
CVE-2024-27298Same product: Parseplatform Parse-Server
CVE-2026-32248Same product: Parseplatform Parse-Server
CVE-2026-30941Same product: Parseplatform Parse-Server
CVE-2026-30848Same product: Parseplatform Parse-Server

Affected Assets

parseplatform
parse-server
9.7.0 · 3.5.0 — 8.6.66 · 9.0.0 — 9.7.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

AC-4 Information Flow Enforcement good match

Information flow enforcement directly requires validating the source of data before allowing transmission or receipt.

IA-3 Device Identification and Authentication good match

Device identification and authentication mandates verifying the source before establishing connections.

SC-23 Session Authenticity good match

Session authenticity mechanisms require validation that communications originate from the expected party.

SC-7 Boundary Protection partial match

Boundary protection at interfaces enforces checks on the origin of incoming communications.

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-03 mostly match
prevents

Authentication directly verifies the source of users/services/hardware, mitigating origin validation failures.

PR.AA-04 mostly match
prevents

Verifying identity assertions enforces origin validation for conveyed claims.

ID.AM-03 partial match
prevents

Documenting authorized flows supports origin validation by defining expected sources.

PR.IR-01 partial match
prevents

Protecting networks from unauthorized access requires origin checks on communication sources.

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.8.20 Networks security partial match
mitigates

Network security controls enforce origin validation at network boundaries.

A.8.21 Security of network services partial match
mitigates

Security of network services includes validating the authenticity of service endpoints.

A.8.22 Segregation of networks partial match
mitigates

Network segregation reduces exposure but does not directly validate origins.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for origin validation of inputs and communications.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles encourage origin checks but do not mandate them.

A.8.28 Secure coding partial match
prevents

Secure coding practices include implementing proper origin validation to prevent spoofing.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (3 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-346
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-346
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-346

References