CVE-2026-40300
Prior to 12.0, With message_edit_history_visibility_policy set to "moves", /api/v1/messages/{id}/history still returns historical content values, allowing low-privilege users to recover text that was edited away from other users' messages.
Does this matter?
Lower severity and a low EPSS score (0.25%). Track it; it rarely justifies an emergency change on its own.
Description
Zulip is an open-source team collaboration tool. Prior to 12.0, With message_edit_history_visibility_policy set to "moves", /api/v1/messages/{id}/history still returns historical content values, allowing low-privilege users to recover text that was edited away from other users' messages. This vulnerability is fixed in 12.0.
- CVSS 4.0
- 6.0 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.25% probability · 16th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-284
- Affected
- zulip/zulip server
- Source
- security-advisories@github.com
References
- https://github.com/zulip/zulip/security/advisories/GHSA-jp8f-mvv6-89crExploit, Vendor Advisory
- https://github.com/zulip/zulip/security/advisories/GHSA-jp8f-mvv6-89crExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.