CVE-2026-32248: Parse Server: Account takeover via operator injection in authentication data identifier

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 1.0%, percentile 61: FIRST’s model estimates a 1.0% chance of exploitation activity in the next 30 days, higher than 61% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes parse-server (npm) >= 9.0.0, < 9.6.0-alpha.12, fixed in 9.6.0-alpha.12; parse-server (npm) < 8.6.38, fixed in 8.6.38. Check your lockfile, including transitive dependencies.

What it is

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0-alpha.12 and 8.6.38, an unauthenticated attacker can take over any user account that was created with an authentication provider that does not validate the format of the user identifier (e.g. anonymous authentication). By sending a crafted login request, the attacker can cause the server to perform a pattern-matching query instead of an exact-match lookup, allowing the attacker to match an existing user and obtain a valid session token for that user's account. Both MongoDB and PostgreSQL database backends are affected. Any Parse Server deployment that allows anonymous authentication (enabled by default) is vulnerable. This vulnerability is fixed in 9.6.0-alpha.12 and 8.6.38.

From the GitHub advisory

Impact

An unauthenticated attacker can take over any user account that was created with an authentication provider that does not validate the format of the user identifier (e.g. anonymous authentication). By sending a crafted login request, the attacker can cause the server to perform a pattern-matching query instead of an exact-match lookup, allowing the attacker to match an existing user and obtain a valid session token for that user's account. Both MongoDB and PostgreSQL database backends are affected. Any Parse Server deployment that allows anonymous authentication (enabled by default) is vulnerable.

Patches

The fix enforces that the user identifier in authentication data is a string before using it in a database query. Non-string values are rejected with a validation error.

Workarounds

Weakness type: CWE-943.

Product: parse-server (npm) · Assigned by: GitHub_M · Published: 2026-03-12

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.95% probability of exploitation activity in the next 30 days; percentile 61.

Timeline

• 2026-03-12 — CVE record published by GitHub_M
• 2026-03-12 — GitHub-reviewed advisory GHSA-5fw2-8jcv-xh87 published (critical)
• 2026-03-13 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-5fw2-8jcv-xh87 github.com
2. CVE.org record CVE-2026-32248 cve.org
3. NVD entry CVE-2026-32248 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com

Critical npm advisories · Today’s Security Digest