Security readout for executives and security teams
Plain-English summary
Microsoft reports a high-severity remote code execution flaw in Windows Routing and Remote Access Service. An authenticated attacker could execute code over the network. This matters most for Windows servers or endpoints using RRAS for routing, VPN, or remote access functions. Microsoft has published an advisory with updates.
Executive priority
Treat as a high-priority patching item for Windows systems running RRAS, especially remote access infrastructure. No active exploitation is confirmed in the provided sources, but successful exploitation could allow full system compromise.
Technical view
CVE-2026-26111 is an integer overflow or wraparound issue in Windows RRAS, associated with CWE-190 and CWE-122. CVSS 3.1 is 8.0: network attack vector, low complexity, low privileges required, user interaction required, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is likely limited to affected Windows versions where RRAS is present and relevant to operations. Listed platforms include multiple Windows 10, Windows 11, and Windows Server releases from 2012 through 2025, including Server Core variants.
Exploitation context
The provided sources do not show known active exploitation, and CISA KEV status is false. Microsoft’s CVSS vector indicates exploitation requires network access, low privileges, and user interaction. Public exploit status is not established in the provided evidence.
Researcher notes
Key unknowns include the exact vulnerable code path, user-interaction condition, and exploit maturity. The CVSS vector and affected-version list come from Microsoft/CVE data. Avoid assuming internet-wide exposure without confirming RRAS deployment and network reachability.
Mitigation direction
- Apply Microsoft updates referenced in the MSRC advisory.
- Prioritize systems with RRAS enabled or reachable over networks.
- If patching is delayed, review Microsoft guidance for supported workarounds.
- Track unsupported or legacy Windows Server exposure separately.
Validation and detection
- Inventory affected Windows versions listed by Microsoft.
- Confirm whether RRAS is enabled or used on each system.
- Verify installation of the relevant Microsoft security update.
- Check exposure of RRAS systems to untrusted networks.
- Monitor Microsoft’s advisory for revisions or new guidance.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-122: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-190: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-26111 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C2.15.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- Windows Routing and Remote Access Service (RRAS) Remote Code Execution VulnerabilityCVE reference · vendor-advisory, patch
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Heap-based Buffer Overflow
Heap-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Integer Overflow or Wraparound
Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.