CVE-2026-97701
Published:November 04, 2026
Updated:November 05, 2026
Zulip is an open-source team collaboration tool. In Zulip Server versions through 12.1, the authenticated POST /messages/render endpoint renders the content parameter without enforcing the normal message length limit used by message send and edit operations. An authenticated user can submit Markdown up to the server body-size limit, causing disproportionate backend CPU consumption, and repeated or concurrent requests can degrade Markdown rendering performance or backend availability for other users. This issue is fixed in version 12.2.
Affected Packages
https://github.com/zulip/zulip.git (GITHUB):
Affected version(s) >=1.3.0 <12.2 || >=2.0.0-rc1 <12.2 || >=3.0-rc1 <12.2 || >=4.0-rc1 <12.2 || >=5.0-rc1 <12.2 || >=6.0-beta1 <12.2 || >=7.0-beta1 <12.2 || >=8.0-beta1 <12.2 || >=9.0-beta1 <12.2 || >=10.0-beta1 <12.2 || >=11.0-beta1 <12.2 || >=12.0-beta1 <12.2Fix Suggestion:
Update to version 12.2Related Resources (8)
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Contact UsCVSS v4
Base Score:
7.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Allocation of Resources Without Limits or Throttling