CISA Adds Four Known Exploited Vulnerabilities to Catalog
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
CISA has added four new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog , based on evidence of active exploitation. CVE-2026-33824 Microsoft Internet Key Exchange (IKE) Service Extensions Double Free Vulnerability CVE-2026-55040 Microsoft SharePoint Weak Authentication Vulnerability CVE-2026-59310 Broadcom VMware vCenter Path Traversal Vulnerability CVE-2026-65400 Apple macOS Improper Authentication Vulnerability These types of vulnerabilities are a frequent attack vector for malicious cyber actors and pose significant risks to the federal enterprise. Binding Operational Directive (BOD) 26-04: Prioritizing Security Updates Based on Risk establishes vulnerability management requirements for Federal Civilian Executive Branch (FCEB) agencies. BOD 26-04 reinforces the importance of the KEV Catalog and requires federal agencies to prioritize rapid remediation of high-risk vulnerabilities, specifically those identified by Common Vulnerabilities and Exposures (CVEs) listed in CISA’s KEV Catalog on publicly exposed assets that grant total control of the asset post-exploitation, while deferring action for lower-risk vulnerabilities. BOD 26-04 further establishes basic expectations for when agencies must check whether threat actors compromised the system before the patch was applied. While BOD 26-04 applies only to FCEB agencies, CISA encourages all organizations to adopt risk-based vulnerability management and prioritize remediation of KEV Catalog vulnerabilities . CISA will continue to add vulnerabilities to the catalog that meet the specified criteria . Aware of an exploited vulnerability not currently listed in the KEV Catalog? Submit it for potential addition through CISA’s KEV Nomination Form . Potential KEV additions must have a CVE ID, evidence of exploitation, and clear mitigation guidance.
CSIRTS triage
- What
- Four vulnerabilities affecting Microsoft IKE Service Extensions, Microsoft SharePoint, Broadcom VMware vCenter, and Apple macOS are actively exploited.
- Who is affected
- Windows systems running IKE Service Extensions, SharePoint deployments, VMware vCenter infrastructure, and macOS systems with Screen Sharing enabled.
- Urgency
- Critical; all four vulnerabilities are actively exploited in the wild and require immediate patching per CISA BOD 26-04.
- Action
- Apply vendor-specific patches immediately for Microsoft IKE Service Extensions, SharePoint, VMware vCenter, and macOS as detailed in respective security advisories.
AI-assisted analysis generated from the source advisory — verify against the original.
Details
Original advisory: https://www.cisa.gov/news-events/alerts/2026/08/18/cisa-adds-four-known-exploited-vulnerabilities-catalog
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2026-33824Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 99.5% of all EPSS-scored CVEs.
- Exploitation confirmedCVE-2026-55040Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 92% of all EPSS-scored CVEs.
- Exploitation confirmedCVE-2026-59310Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 83% of all EPSS-scored CVEs.
- Exploitation confirmedCVE-2026-65400Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 52% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-33824 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-55040 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-59310 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-65400 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- unknownexploitedApple security advisory (AV26-823) – Update 1cccs
- unknownexploitedVMware security advisory (AV26-763) – Update 1cccs
- unknownexploitedMicrosoft security advisory – August 2026 monthly rollup (AV26-804) – Update 1cccs
- criticalexploitedCVE-2026-33824: Microsoft Internet Key Exchange (IKE) Service Extensions Double Free Vulnerabilitycisa-kev
- criticalexploitedCVE-2026-65400: Apple macOS Improper Authentication Vulnerabilitycisa-kev
- criticalexploitedCVE-2026-59310: Broadcom VMware vCenter Path Traversal Vulnerabilitycisa-kev
- criticalexploitedCVE-2026-55040: Microsoft SharePoint Weak Authentication Vulnerabilitycisa-kev
- unknownexploitedVMWare Products Multiple Vulnerabilitieshkcert
- high[NEW] [medium] Apple macOS (Sonoma, Sequoia and Tahoe): Vulnerability enables security feature bypasscert-bund
- unknownexploitedNCSC-2026-0280 [1.01] [M/H] Vulnerability patched in macOS Screen Sharing by Applencsc-nl
- high[NEW] [high] VMware Products: Multiple vulnerabilitiescert-bund
- unknownNCSC-2026-0280 [1.00] [M/H] Vulnerability fixed in macOS Screen Sharing by Applencsc-nl
Recent advisories for CISA Adds Four
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- highexploitedCISA Adds Four Known Exploited Vulnerabilities to Catalogcisa · 2026-07-21
- criticalexploitedCISA Adds Four Known Exploited Vulnerabilities to Catalogcisa · 2026-07-14
- highexploitedCISA Adds Four Known Exploited Vulnerabilities to Catalogcisa · 2026-06-23
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