# CVE-2026-121415: Parse Server before 8.6.111 and 9.0.0 before 9.10.6-alpha.3 Field Corruption via Null Dot Notation Key

Status: published. Published: 2026-11-03. Updated: 2026-11-03.

Parse Server before 8.6.111 and 9.0.0 before 9.10.6-alpha.3 on MongoDB skips field type validation for null-valued dot notation keys, allowing sub-documents to be written beneath Pointer, Number, String, Date, or Boolean fields. Any client with write access, including unauthenticated clients where public writes are permitted, can corrupt field values, make objects unreadable via internal date fields, or break atomic operations on number fields.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/parse-community/parse-server/pull/10804
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/parse-community/parse-server/pull/10805

## Affected products and versions

- parse-community / parse-server (parse-server): ≥ 9.0.0; < 9.10.6-alpha.3 (affected, semver); 9.10.6-alpha.3 (unaffected, semver). Source: CNA: VulnCheck
- parse-community / parse-server (parse-server): ≥ 0; < 8.6.111 (affected, semver); 8.6.111 (unaffected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 6.3 (medium); CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 3.7 (low); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-20

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/parse-community/parse-server/security/advisories/GHSA-655c-2xf3-77x9 (CNA: VulnCheck; vendor-advisory)

- https://github.com/parse-community/parse-server/pull/10804 (CNA: VulnCheck; patch, issue-tracking)

- https://github.com/parse-community/parse-server/pull/10805 (CNA: VulnCheck; patch, issue-tracking)

- https://www.vulncheck.com/advisories/parse-server-before-8.6.111-and-9.0.0-before-9.10.6-alpha.3-field-corruption-via-null-dot-notation-key (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-121415; retrieved 2026-11-03; source updated 2026-11-03

Revision: 2b096c68310cc310b99fc6f30f9a42d03541dc5b5fc432438b6af30dc072b4ab

Canonical: https://y2.dev/cve/CVE-2026-121415

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