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Out-of-bounds WriteWeakness · CWE-787

CVE-2026-22211

MEDIUM · 5.1 CVSS v4.0 Published 2026-01-14
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
56/100
Remediation priority · Elevated
No privileges Zero-click

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 · unedited
TinyOS versions up to and including 2.1.2 contain a global buffer overflow vulnerability in the printfUART formatted output implementation used within the ZigBee / IEEE 802.15.4 networking stack. The implementation formats output into a fixed-size global buffer and concatenates strings for %s format specifiers using strcat() without verifying remaining buffer capacity. When printfUART is invoked with a caller-controlled string longer than the available space, the unbounded sprintf/strcat sequence writes past the end of debugbuf, resulting in global memory corruption. This can cause denial of service, unintended behavior, or information disclosure via corrupted adjacent global state or UART output.

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 confidence

TinyOS 2.1.2 and earlier contain a global buffer overflow in the printfUART function used by the ZigBee/IEEE 802.15.4 networking stack. The function uses a fixed-size global debugbuf and concatenates strings via strcat() for %s format specifiers without checking buffer capacity, allowing caller-controlled strings to overflow and corrupt adjacent global memory.

MitigationReplace unbounded strcat() calls with length-bounded functions like strncpy() or snprintf(), and add explicit length validation before string concatenation to ensure the formatted output fits within debugbuf.

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
Local
Complexity
Low
Privileges
None
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify TinyOS installation
    Search for TinyOS directories, build files (.nc, .tos), or embedded firmware images that contain TinyOS artifacts. Look for file headers, SDK paths, or firmware metadata referencing TinyOS.
    Affected if TinyOS is present in the environment
  2. Determine TinyOS version
    Locate version information in TinyOS installation directories, build configuration files, or firmware metadata. Compare the installed or compiled version against 2.1.2.
    Affected if The TinyOS version is 2.1.2 or earlier
  3. Locate printfUART function
    Search source code or disassembly for the printfUART function definition. This function is part of the ZigBee/IEEE 802.15.4 networking stack.
    Affected if The printfUART function exists in the deployed code
  4. Identify %s format specifier usage with debug output
    Search for calls to printfUART or related debug functions that use %s format specifiers with external or user-controlled input strings.
    Affected if %s format specifiers are used with potentially caller-controlled strings in debug output functions
  5. Inspect debugbuf buffer configuration
    Examine the global debugbuf declaration in the printfUART implementation to confirm it uses a fixed-size buffer and strcat() for string concatenation without length checking.
    Affected if debugbuf is a fixed-size global buffer using unbounded strcat() for %s handling

The environment is affected if TinyOS version 2.1.2 or earlier is deployed and the printfUART function with %s format specifiers processes external input strings through a fixed-size global buffer using unbounded strcat().

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Replace unbounded strcat() calls with length-bounded functions like strncpy() or snprintf(), and add explicit length validation before string concatenation to ensure the formatted output fits within debugbuf.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-22211 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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