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CVE-2026-45691

Nextcloud: Bypass of second factor authentication on DAV endpoints

Published: Jun 1, 2026Updated: Jul 22, 2026 Sources: CVE List NVDCWE-287
5.9MEDIUM
NVD MITRE
EPSS Score
0.3%
Top 78.8%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

Description

Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, a pre-2FA session cookie (created after successful password authentication but before TOTP completion) could be reused as a Bearer token to authenticate against DAV endpoints, granting read/write access and bypassing mandatory two-factor authentication. It is recommended that the Nextcloud Server is upgraded to 33.0.3 or 32.0.9. It is recommended that the Nextcloud Enterprise Server is upgraded to 33.0.3, 32.0.9, 31.0.14.5, 30.0.17.9 or 29.0.16.16

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:HPR:LUI:NS:UC:LI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:HIntegrity
High
A:NAvailability
None
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Weaknesses

CWE-287

Affected Products

nextcloud
oss-project·DEaka nextcloud server
nextcloud serverSaaSSaaS Service
Cloud & SaaS / saas-application
security-advisoriesSaaSSaaS Service
Cloud & SaaS / saas-application

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Initial Access
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References

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-mp6x-g55j-w9jw
github.com
https://github.com/nextcloud/server/pull/59758
github.com
https://hackerone.com/reports/3573399
hackerone.com

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