CVE-2026-55040
Microsoft SharePoint Server Security Feature Bypass Vulnerability
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Listed in CISA KEV
- Fix
- Fixed in 16.0.5561.1001, 16.0.10417.20175, 16.0.19725.20434
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: active
- Automatable: yes
- Technical impact: total
Summary
Microsoft SharePoint Server is affected by this vulnerability, which involves weak authentication. An unauthorized attacker on the network could use it to bypass a security feature.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original description
Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.
Timeline
- CISA SSVC assessment
Exploitation: active · Automatable: yes · Technical impact: total
- CVE published
- Added to CISA KEV
CISA has evidence of exploitation in the wild
- CISA remediation deadline
Due date for US federal agencies to patch
- EPSS reached 10%
FIRST estimates at least a 10% chance of exploitation in the next 30 days
- Record last updated
Affected versions
- Microsoft Microsoft SharePoint Enterprise Server 2016
From 16.0.0 · fixed in 16.0.5561.1001
- Microsoft Microsoft SharePoint Server 2019
From 16.0.0 · fixed in 16.0.10417.20175
- Microsoft Microsoft SharePoint Server Subscription Edition
From 16.0.0 · fixed in 16.0.19725.20434