CVE-2026-31196
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 · uneditedOS command injection vulnerability in the traceroute diagnostic handler in /bin/httpd_clientside in ALTICE LABS / SFR France GR140DG Fibre Router with firmware 3GN8020801R13, 3GN8020802R0A, or 3GN8020803R0A inserts unsanitized user input into a system() call, allowing authenticated remote attackers to execute arbitrary commands as root via crafted destAddr parameters using shell command substitution.
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 · high confidenceA command injection vulnerability exists in the traceroute diagnostic feature of the httpd_clientside daemon on the GR140DG router. The destAddr parameter is passed unsanitized to a system() call, allowing authenticated attackers to inject arbitrary shell commands that execute with root privileges through shell command substitution.
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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Identify the device modelCheck the router model number via web interface, command line (e.g., 'cat /proc/cpuinfo', 'nvram get model'), or physical labelAffected if Device is not a GR140DG router (different models may share similar software but this CVE specifically affects GR140DG)
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Verify httpd_clientside daemon is runningRun 'ps | grep httpd_clientside' or 'ps aux | grep -i httpd' via SSH/telnet if available, or check process list via web UI diagnostics if exposedAffected if The httpd_clientside process is not running (the vulnerable code would not be active)
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Confirm traceroute diagnostic feature is accessibleCheck if the diagnostic/traceroute page is exposed via the web interface (typically /diagnostics.traceroute.asp or similar), or attempt to access the feature if you have admin credentialsAffected if The traceroute diagnostic functionality is exposed and accessible to authenticated users (the vulnerable code path requires this feature to be used)
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Check for unauthorized shell command executionReview system logs (/var/log/messages, /var/log/syslog) for suspicious entries containing shell metacharacters (|, ;, $, `, ||, &&) in what appears to be traceroute invocations, or look for unexpected processes spawned by rootAffected if Logs show traceroute commands with injected shell syntax, or unexpected root-level processes appear that were not initiated by legitimate administrators
A GR140DG router with the httpd_clientside daemon running and traceroute diagnostic feature exposed to authenticated users is potentially affected if logs show anomalous command patterns or unexpected root processes.
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 dataThe vendor should release a firmware patch that properly sanitizes all user inputs before passing them to system() calls, ideally by using safer APIs or input validation. Until a patch is available, restrict access to the diagnostic functions and monitor for unauthorized access.
- Consultation8.0 h
- Implementation16.0 h
- Testing8.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-31196 — 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-2026-31196 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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