CVE-2026-30835
Parse Server: Malformed `$regex` query leaks database error details in API response
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.7 and 9.5.0-alpha.6, malformed $regex query parameter (e.g. [abc) causes the database to return a structured error object that is passed unsanitized through the API response. This leaks database internals such as error messages, error codes, code names, cluster timestamps, and topology details. The vulnerability is exploitable by any client that can send query requests, depending on the deployment's permission configuration. This issue has been patched in versions 8.6.7 and 9.5.0-alpha.6.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.9
Parse Server: Malformed `$regex` query leaks database error details in API response
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.7 and 9.5.0-alpha.6, malformed $regex query parameter (e.g. [abc) causes the database to return a structured error object that is passed unsanitized through the API response. This leaks database internals such as error messages, error codes, code names, cluster timestamps, and topology details. The vulnerability is exploitable by any client that can send query requests, depending on the deployment's permission configuration. This issue has been patched in versions 8.6.7 and 9.5.0-alpha.6.
- Record
CVE-2026-30835- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-209
- Updated
- 2026-11-02
EUVDEUVD-2026-10061
6.9
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.7 and 9.5.0-alpha.6, malformed $regex query parameter (e.g. [abc) causes the database to return a structured error object that is passed unsanitized through the API response. This leaks database internals such as error messages, error codes, code names, cluster timestamps, and topology details. The vulnerability is exploitable by any client that can send query requests, depending on the deployment's permission configuration. This issue has been patched in versions 8.6.7 and 9.5.0-alpha.6.
- Record
EUVD-2026-10061- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-9cp7-3q5w-j92g
6.9
parse-server: Malformed `$regex` query leaks database error details in API response
Impact
A malformed $regex query parameter (e.g. [abc) causes the database to return a structured error object that is passed unsanitized through the API response. This leaks database internals such as error messages, error codes, code names, cluster timestamps, and topology details. The vulnerability is exploitable by any client that can send query requests, depending on the deployment's permission configuration.
Patches
The fix sanitizes database error objects so that only a generic "An internal server error occurred" message is returned to clients, while the detailed error is logged server-side. The fix respects the enableSanitizedErrorResponse server option.
Workarounds
There is no workaround other than upgrading. The error leakage occurs in the query execution layer and cannot be mitigated through server configuration or client-side changes.
Resources
- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-9cp7-3q5w-j92g
- Fix in Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.5.0-alpha.6
- Fix in Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.7
- Record
GHSA-9cp7-3q5w-j92g- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-209
- Updated
- 2026-11-02
NVD
6.9
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.7 and 9.5.0-alpha.6, malformed $regex query parameter (e.g. [abc) causes the database to return a structured error object that is passed unsanitized through the API response. This leaks database internals such as error messages, error codes, code names, cluster timestamps, and topology details. The vulnerability is exploitable by any client that can send query requests, depending on the deployment's permission configuration. This issue has been patched in versions 8.6.7 and 9.5.0-alpha.6.
- Record
CVE-2026-30835- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-209
- Updated
- 2026-11-02
OSV
6.9
Parse Server: Malformed `$regex` query leaks database error details in API response
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.7 and 9.5.0-alpha.6, malformed $regex query parameter (e.g. [abc) causes the database to return a structured error object that is passed unsanitized through the API response. This leaks database internals such as error messages, error codes, code names, cluster timestamps, and topology details. The vulnerability is exploitable by any client that can send query requests, depending on the deployment's permission configuration. This issue has been patched in versions 8.6.7 and 9.5.0-alpha.6.
- Record
CVE-2026-30835- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-209
- Updated
- 2026-11-02
OSVGHSA-9cp7-3q5w-j92g
6.9
parse-server: Malformed `$regex` query leaks database error details in API response
Impact
A malformed $regex query parameter (e.g. [abc) causes the database to return a structured error object that is passed unsanitized through the API response. This leaks database internals such as error messages, error codes, code names, cluster timestamps, and topology details. The vulnerability is exploitable by any client that can send query requests, depending on the deployment's permission configuration.
Patches
The fix sanitizes database error objects so that only a generic "An internal server error occurred" message is returned to clients, while the detailed error is logged server-side. The fix respects the enableSanitizedErrorResponse server option.
Workarounds
There is no workaround other than upgrading. The error leakage occurs in the query execution layer and cannot be mitigated through server configuration or client-side changes.
Resources
- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-9cp7-3q5w-j92g
- Fix in Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.5.0-alpha.6
- Fix in Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.7
- Record
GHSA-9cp7-3q5w-j92g- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-209
- Updated
- 2026-11-02
OSVBIT-parse-2026-30835 No score
Parse Server: Malformed `$regex` query leaks database error details in API response
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.7 and 9.5.0, malformed $regex query parameter (e.g. [abc) causes the database to return a structured error object that is passed unsanitized through the API response. This leaks database internals such as error messages, error codes, code names, cluster timestamps, and topology details. The vulnerability is exploitable by any client that can send query requests, depending on the deployment's permission configuration. This issue has been patched in versions 8.6.7 and 9.5.0.
- Record
BIT-parse-2026-30835- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
parse-servernpm |
9.0.0 up to 9.5.0-alpha.6 | 9.5.0-alpha.6 |
parse-servernpm |
before 8.6.7 | 8.6.7 |
parseBitnami |
before 9.5.0 | 9.5.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-30835 is a medium vulnerability (CVSS 6.9) in Parse-community Parse-server, published March 6, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.37%, the 31st percentile. Fixed in parse-server 9.5.0-alpha.6.
References
github.com/parse-community/parse-server/security/advisories/GHSA-9cp7-3q5w-j92g
github.com/parse-community/parse-server/releases/tag/8.6.7
github.com/parse-community/parse-server/releases/tag/9.5.0-alpha.6
nvd.nist.gov/vuln/detail/CVE-2026-30835
github.com/advisories/GHSA-9cp7-3q5w-j92g
github.com/CVEProject/cvelistV5/tree/main/cves/2026/30xxx/CVE-2026-30835.json
github.com/parse-community/parse-server