CVE-2026-115933: Forged signed tokens let any registered user take over other users and organizations

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.2%

EPSS score, percentile 16.3 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

9.9 Critical

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (3)

Which versions are affected?

Affected

• from 2.15.0 to before 2.25.3

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Workaround (from the CVE record)

If you do not use channels that rely on the Postiz browser extension, block POST /integrations/extension-refresh at your reverse proxy. This removes the main signing route; the team invitation route remains.

Set DISABLE_REGISTRATION=true. The attacker needs an ordinary account, so closing self-registration limits exposure to people who already hold one. This reduces reach, it does not close the issue.

Advisories and patches

• a5affe62 (Patch)
• GAdvisory (Vendor advisory)
• v2.25.3 (Release notes)

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Versions not listed are: unaffected.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

Postiz signs its session, invitation and password reset tokens with one shared secret and without any marker of what a token is for. A route that refreshes the credentials of a browser-extension channel signed data taken from the request itself and stored the result where the requesting user can read it back. A user could therefore obtain a validly signed token containing any claims they choose,…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-115933 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 24 Oct 2026.
• The CVE record carries a CVSS v3.1 base score of 9.9 (Critical), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.2% (percentile 16.3), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• The credits in the CVE record name Anthropic (Claude) as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

Forged signed tokens let any registered user take over other users and organizations

Postiz signs its session, invitation and password reset tokens with one shared secret and without any marker of what a token is for. A route that refreshes the credentials of a browser-extension channel signed data taken from the request itself and stored the result where the requesting user can read it back. A user could therefore obtain a validly signed token containing any claims they choose, which the application accepts as a session, as an organization invitation with a chosen role, as a password reset or as an enterprise provisioning token. A second, narrower route that creates team invitations signs extra fields from the request body in the same way.

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline