Security readout for executives and security teams
Plain-English summary
CVE-2026-27847 is a critical flaw in specified Linksys MR9600 and MX4200 firmware. An unauthenticated network attacker may manipulate a TLS-SRP handshake to add credentials to the device database, then access a protected service. This can affect confidentiality, integrity, and availability if vulnerable devices are reachable.
Executive priority
Treat as urgent for environments using the listed Linksys firmware, especially where router services are reachable beyond trusted networks. The issue is critical because it may allow unauthenticated access to protected services without user interaction.
Technical view
The CVE describes SQL injection during TLS-SRP handshake processing caused by improper neutralization of special elements, mapped to CWE-89. Affected versions listed are MR9600 1.0.4.205530 and MX4200 1.0.13.210200. CVSS 3.1 is 9.8: network attack vector, low complexity, no privileges, no user interaction, high C/I/A impact.
Likely exposure
Exposure is most concerning for affected Linksys routers with the relevant protected service reachable from untrusted networks. The provided data does not state whether the vulnerable service is exposed by default, internet-facing, or limited to LAN access.
Exploitation context
The source bundle does not indicate known active exploitation, and CISA KEV status is false. Public details state the attack is unauthenticated, network-based, and low complexity, but no exploit maturity or in-the-wild activity is cited.
Researcher notes
The affected-products data contains a nuance: the description says both MR9600 and MX4200 versions are affected, while the structured affected entry marks MX4200 default status as unaffected. Validate against the CVE record and vendor guidance before broad conclusions. No patch details are included in the provided sources.
Mitigation direction
- Identify MR9600 and MX4200 devices and record firmware versions.
- Check Linksys guidance for fixed firmware or official mitigations.
- Limit access to router services from untrusted networks where operationally possible.
- Prioritize replacement or isolation if no vendor fix is available.
Validation and detection
- Compare device firmware against MR9600 1.0.4.205530 and MX4200 1.0.13.210200.
- Review firewall and management exposure for affected devices.
- Monitor device logs for unexpected authentication or database-related anomalies.
- Track the CVE record and SySS advisory for updates.
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-89: Database access and collection lookup
Injection into data stores can inform collection, data access, and exfiltration detection reviews. 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 lookupDatabase behavior lookup
The CVE wording references database injection or access, so collection and exfiltration review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-27847 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2025-009.txtCVE reference · third-party-advisory, technical-description
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.
Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.