FreeBSDOperating system
CVE-2026-49416
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 · uneditedThe CONS_HISTORY ioctl handler did not adequately validate the requested history size. A large value caused an integer overflow in the buffer size calculation, resulting in a heap allocation smaller than expected. Subsequent initialization of the buffer wrote beyond the end of the allocation. An unprivileged local user with access to a vt(4) device can trigger an out-of-bounds write in the kernel, potentially escalating privileges.
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 confidenceInteger overflow in CONS_HISTORY ioctl allows unvalidated history size to cause heap allocation smaller than expected, leading to out-of-bounds write in vt(4) kernel driver. Unprivileged local user with vt device access can trigger this to potentially escalate privileges.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
FreeBSDOperating system
= 14.3= 14.4= 15.0CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/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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Check FreeBSD versionRun 'uname -r' or 'freebsd-version -k' to identify the installed FreeBSD versionAffected if Version is 14.3, 14.4, or 15.0
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Identify if vt driver is activeCheck kernel module loaded via 'kldstat | grep vt' or check active console with 'vidcontrol -i mode'Affected if vt driver is loaded or active as the console driver
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Verify vt device access permissionsList /dev/ttyv* device files and check group/world read/write permissions with 'ls -la /dev/ttyv*'Affected if Unprivileged users have read or write access to vt devices (e.g., group 'tty' with write, or world-readable/writable)
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Confirm CONS_HISTORY ioctl exists in vt driverInspect vt driver source or verify driver supports ioctl interface via 'vt(4)' man page and check for CONS_HISTORY supportAffected if The vt driver binary supports the CONS_HISTORY ioctl command
A user is affected if they run FreeBSD 14.3, 14.4, or 15.0 with the vt driver active and unprivileged local users have access to vt devices that expose the vulnerable CONS_HISTORY ioctl interface.
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 kernel patch that adds proper bounds checking and overflow validation for history size parameter in CONS_HISTORY ioctl handler before buffer allocation.
Fix this in FreeBSD
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,416.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-49416 — 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-2026-49416 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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