Parse Server has a session field immutability bypass via falsy-value guard

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

5.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-34574: 0.22% estimated exploitation activity in the next 30 days; percentile 12.32 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact An authenticated user can bypass the immutability guard on session fields (expiresAt, createdWith) by sending a null value in a PUT request to the session update endpoint. This allows nullifying the session expiry, making the session valid indefinitely and bypassing configured session length policies. Patches The truthiness-based guard checks were replaced with key-presence checks that reject any value for protected session fields, including null. Workarounds There is no known workaround. A beforeSave trigger on Session could be used to reject null values for expiresAt and createdWith.

Published by the source

1 Apr 2026, 00:03 UTC

Last modified by the source

6 Apr 2026, 15:27 UTC

Source last checked

26 Oct 2026, 12:47 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-f6j3-w9v3-cq22

2. Revision 2 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-f6j3-w9v3-cq22

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# Patch Next advisory brief: CVE-2026-34574

Advisory: Parse Server has a session field immutability bypass via falsy-value guard
IDs: CVE-2026-34574, GHSA-f6j3-w9v3-cq22
Record: https://patchnext.com/advisories/cve-2026-34574 (revision 3, source checked 26 Oct 2026, 12:47 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: parse-server 9.7.0-alpha.14, 8.6.69. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm parse-server: affected >= 9.0.0, < 9.7.0-alpha.14; < 8.6.69; fixed in 8.6.69, 9.7.0-alpha.14

## Suggested inspection (read-only)
- `npm ls parse-server --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on parse-server.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-f6j3-w9v3-cq22 (OSV record GHSA-f6j3-w9v3-cq22 lists affected ranges: npm parse-server >=9.0.0 =0 <8.6.69 (fixed))
- Verified: https://github.com/advisories/GHSA-f6j3-w9v3-cq22 (GitHub-reviewed advisory GHSA-f6j3-w9v3-cq22 lists affected ranges: npm parse-server >=9.0.0 =0 <8.6.69)

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