CVE-2026-25741: Zulip is an open-source team collaboration tool. Prior to commit bf28c82dc9b1f630fa8e9106358771b20a0040f7, the API endpoint for creating a card update...

Description

Zulip is an open-source team collaboration tool. Prior to commit bf28c82dc9b1f630fa8e9106358771b20a0040f7, the API endpoint for creating a card update session during an upgrade flow was accessible to users with only organization member privileges. When the associated Stripe Checkout session is completed, the Stripe webhook updates the organization’s default payment method. Because no billing-specific authorization check is enforced, a regular (non-billing) member can change the organization’s payment method. This vulnerability affected the Zulip Cloud payment processing system, and has been patched as of commit bf28c82dc9b1f630fa8e9106358771b20a0040f7. Self-hosted deploys are no longer affected and no patch or upgrade is required for them.

Metrics

CVSS 3.1

7.1/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L

EPSS Probability

0.27%

19.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-863

References

Timeline

Published: Feb 26, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-25741?

Zulip is an open-source team collaboration tool. Prior to commit bf28c82dc9b1f630fa8e9106358771b20a0040f7, the API endpoint for creating a card update session during an upgrade flow was accessible to users with only organization member privileges. When the associated Stripe Checkout session is completed, the Stripe webhook updates the organization’s default payment method. Because no billing-specific authorization check is enforced, a regular (non-billing) member can change the organization’s payment method. This vulnerability affected the Zulip Cloud payment processing system, and has been patched as of commit bf28c82dc9b1f630fa8e9106358771b20a0040f7. Self-hosted deploys are no longer affected and no patch or upgrade is required for them.

How severe is CVE-2026-25741?

CVE-2026-25741 has a CVSS score of 7.1/10 (HIGH severity). The EPSS model estimates a 0.27% probability of exploitation in the next 30 days.

How do I fix CVE-2026-25741?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.