Microsoft Exchange Server SE: Cross-site request forgery leading to spoofing
Summary
A cross-site request forgery (CSRF, CWE-352) flaw in Microsoft Exchange Server Subscription Edition (SE) allows an unauthorized attacker to perform spoofing over the network. Exploitation requires that a user is tricked into an action, for example by clicking a crafted link while logged in to OWA. Confidentiality impact is none and integrity impact is high according to the CVSS vector. No public exploitation or proof of concept is known.
Affected
- Exchange Server Subscription Edition RTM, versions 15.02.0.0 up to but excluding 15.02.2562.057 (according to the CNA record)
- Exchange 2016 and 2019: not confirmed as affected; they no longer receive security updates
Fixed in
- Exchange Server SE RTM: security update SU12 (KB5133453), build 15.2.2562.57, released 10 November 2026
- Install the November 2026 Windows Server updates in the same window, as the Exchange SU alone does not resolve an instability issue from October 2026 Windows updates
Workaround
Unknown.
Exploitation
- Not known to be exploited in the wild
- Microsoft rates exploitation as less likely and the vulnerability as not publicly disclosed
- No public proof of concept found
- Not listed in CISA KEV according to a third-party mirror; check the CISA KEV catalogue directly
Our recommendation
- Patch Exchange Server SE to SU12 (KB5133453) and install the November 2026 Windows Server updates in the same maintenance window
- Check whether OWA, ECP and EWS are reachable from the internet and restrict exposure where possible
- Migrate any Exchange 2016 or 2019 servers, as they no longer receive security patches
- Prioritise the Windows Search flaw CVE-2026-116928 from the same patch cycle
- Re-check the NVD record and CISA KEV once analysis is published
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Spoofing – Microsoft Exchange Server
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Server software (Exchange, SharePoint …)
- Updates (KB)
- KB5133453
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-118152 msrc.microsoft.com
- Microsoft Support: KB5133453 Exchange Server SE SU12 support.microsoft.com
- Microsoft Tech Community: November 2026 Exchange Server security updates techcommunity.microsoft.com
- Exchange servers may become unstable after October 2026 Windows updates techcommunity.microsoft.com
- Rapid7: Patch Tuesday November 2026 www.rapid7.com
- Strix: CVE-2026-118152 (third-party mirror) www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 12:13.
Original description (NVD)
Cross-site request forgery (csrf) in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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