Security readout for executives and security teams
Plain-English summary
CVE-2026-27512 affects the Tenda F3 router administrative interface. A crafted link or request could make a browser treat reflected content as active HTML because the response lacks the nosniff protection header. The practical risk is script execution in the router admin context after user interaction.
Executive priority
Treat this as a moderate router-management exposure. It is not supported as actively exploited in the provided sources, but administrative interfaces are high-value. Prioritize inventory, management-plane restriction, and vendor update tracking.
Technical view
The issue is content-type confusion in Shenzhen Tenda F3 firmware V12.01.01.55_multi. Responses omit X-Content-Type-Options: nosniff and can reflect attacker-influenced content. Under affected browser MIME-sniffing behavior, this can become reflected script execution. CVSS 3.1 is 6.1, network reachable, low complexity, no privileges required, user interaction required.
Likely exposure
Exposure is most relevant for environments with Tenda F3 routers using firmware V12.01.01.55_multi, especially where the administrative interface is reachable from user browsers or untrusted networks. The source bundle does not establish broader affected versions.
Exploitation context
The record is not marked CISA KEV, and the supplied sources do not state active exploitation. Exploitation requires user interaction and browser behavior that interprets the reflected response as active HTML. The impact is limited confidentiality and integrity loss in the administrative interface context.
Researcher notes
The supplied metadata has an affected version field of 0, while the description names firmware V12.01.01.55_multi. Treat version scope as incomplete until confirmed by vendor or advisory updates. Do not assume unrelated Tenda models or firmware are affected.
Mitigation direction
- Check Tenda and VulnCheck guidance for official firmware updates or workarounds.
- Restrict router administration to trusted management networks only.
- Disable remote administrative access where it is not required.
- Avoid opening untrusted links while authenticated to the router admin interface.
- Use modern browsers with strict MIME-handling protections where possible.
Validation and detection
- Inventory Tenda F3 devices and confirm firmware version V12.01.01.55_multi exposure.
- Verify whether the admin interface emits X-Content-Type-Options: nosniff.
- Confirm whether attacker-influenced input is reflected in administrative responses.
- Review administrative access paths for internet or guest-network reachability.
- Monitor vendor and CVE records for updated affected-version or remediation details.
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-116: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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 lookupCVE-2026-27512 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
- Medium
- CVSS
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
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.
SSVC decision data
CVSS vector scores
2 official scoresWe 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:R/S:C/C:L/I:L/A:N2.82.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
5.1MediumVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://www.tendacn.com/product/F3CVE reference, VulnCheck · product
- https://www.vulncheck.com/advisories/tenda-f3-reflected-script-execution-via-missing-nosniff-headerCVE reference, VulnCheck · third-party-advisory
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 Encoding or Escaping of Output
Improper Encoding or Escaping of Output represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.