CVE-2026-97701
Full vulnerability record from the local CVENow database.
Description
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.
Severity
MEDIUM
CVSS score
6.5
(v3.1)
Vulnerability status
Received
Source identifier
Published
2026-11-04 19:17:41.793000
Last modified
2026-11-04 19:17:41.793000
View original CVE JSON
{
"id": "CVE-2026-97701",
"sourceIdentifier": "[email protected]",
"published": "2026-11-04T19:17:41.793",
"lastModified": "2026-11-04T19:17:41.793",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "zulip",
"product": "zulip",
"versions": [
{
"version": "< 12.2",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.8,
"impactScore": 3.6
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-770"
}
]
}
],
"references": [
{
"url": "https://github.com/zulip/zulip/commit/31773c77c501391ede0fa8ec727f39508664e0ae",
"source": "[email protected]"
},
{
"url": "https://github.com/zulip/zulip/commit/4d94dd2ee6337a4b3351694dd314a45d3fe11031",
"source": "[email protected]"
},
{
"url": "https://github.com/zulip/zulip/pull/39913",
"source": "[email protected]"
},
{
"url": "https://github.com/zulip/zulip/releases/tag/12.2",
"source": "[email protected]"
},
{
"url": "https://github.com/zulip/zulip/security/advisories/GHSA-m257-w4r5-5rmf",
"source": "[email protected]"
},
{
"url": "https://zulip.readthedocs.io/en/latest/overview/changelog.html#zulip-server-12-2",
"source": "[email protected]"
}
]
}