CVE-2026-6157
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA vulnerability was detected in Totolink A800R 4.1.2cu.5137_B20200730. This impacts the function setAppEasyWizardConfig in the library /lib/cste_modules/app.so. The manipulation of the argument apcliSsid results in buffer overflow. The attack can be executed remotely. The exploit is now public and may be used.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceBuffer overflow vulnerability in Totolink A800R router firmware (4.1.2cu.5137_B20200730) allows remote attackers to overflow the apcliSsid parameter in the setAppEasyWizardConfig function within the /lib/cste_modules/app.so library. The high CVSS score (8.8) reflects the ability to exploit this remotely with low complexity, potentially allowing arbitrary code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm device model is Totolink A800RAccess the router admin interface or check the device label/marketing materials to verify the exact model numberAffected if Device is not a Totolink A800R router
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Check installed firmware versionLog into the router admin panel (typically at 192.168.0.1 or 192.168.1.1) and navigate to System Status or Firmware Upgrade page to view the current firmware versionAffected if Firmware version matches or predates 4.1.2cu.5137_B20200730
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Verify vulnerable library existsAccess router via SSH or telnet (if enabled) and check for the existence of /lib/cste_modules/app.soAffected if File /lib/cste_modules/app.so exists on the device
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Check if remote management is enabledIn the router admin interface, examine the Remote Management, Web Management, or Access Control settings to determine if HTTP/HTTPS management is accessible from the WAN interfaceAffected if Remote management (WAN access) is enabled for the router admin interface
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Inspect the vulnerable function in the libraryUse strings or binwalk on /lib/cste_modules/app.so to verify the presence of setAppEasyWizardConfig functionAffected if Function setAppEasyWizardConfig is found in the app.so library
The device is affected if it is a Totolink A800R running firmware version 4.1.2cu.5137_B20200730 or earlier, with the vulnerable /lib/cste_modules/app.so library present and remote management exposed to the WAN.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply vendor firmware update if available; if no patch exists, isolate the device on a restricted network segment and disable unnecessary remote management interfaces to reduce attack surface.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
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Free · runs locallyCheck whether your project pulls in CVE-2026-6157 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-6157 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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