CVE-2026-21373
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 · uneditedMemory Corruption when accessing an output buffer without validating its size during IOCTL processing.
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 confidenceMemory corruption vulnerability in IOCTL processing where the output buffer is accessed without validating its size, allowing potential out-of-bounds memory writes beyond allocated buffer boundaries.
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 dataall versionsall versionsall versionsall versionsall versionsall versionsall versionsall versionsCVSS 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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Identify the Qualcomm chip or firmware in useCheck system information, device specifications, or firmware dumps to determine if the system uses any of the affected Qualcomm components: Aqt1000, Cologne, Fastconnect 6200/6700/6800/6900/7800, or Qca0000. This may be visible in /proc/cpuinfo, device tree files, firmware filenames, or chipset documentation.Affected if The system incorporates any of the listed Qualcomm firmware products (Aqt1000, Cologne, Fastconnect 6200/6700/6800/6900/7800, or Qca0000).
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Determine if IOCTL interface is actively usedMonitor system calls or API calls that invoke IOCTL operations targeting the affected Qualcomm firmware components. Check driver or firmware module logs for IOCTL command invocations. Look for ioctl() calls with file descriptors associated with wireless or connectivity drivers.Affected if IOCTL commands are being sent to drivers or firmware modules that interface with the affected Qualcomm components.
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Inspect IOCTL handler code for buffer size validationIf source code or disassembly is available, examine the IOCTL handler functions for the affected firmware modules. Search for memory copy operations (such as memcpy, copy_to_user, or equivalent) that occur without preceding size parameter validation against the output buffer allocation.Affected if IOCTL handlers perform memory copy operations to output buffers without first validating that the user-provided size matches or does not exceed the allocated buffer size.
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Check for memory corruption indicatorsRun memory diagnostics, enable kernel debugging features (such as KASAN or similar memory sanitizers if available), or review system crash dumps and logs for symptoms of heap or stack corruption, unexpected memory writes, or buffer overflow errors occurring in firmware or driver contexts.Affected if Memory corruption events, unexpected crashes, or abnormal memory access patterns are observed in logs or diagnostics linked to IOCTL processing paths for the affected firmware.
You are affected if your system uses any of the listed Qualcomm firmware products (Aqt1000, Cologne, Fastconnect 6200/6700/6800/6900/7800, Qca0000) and the IOCTL interface to those components is actively used without proper buffer size validation in the handler code.
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 dataAdd explicit buffer size validation in IOCTL handlers to verify user-provided size parameters match the allocated buffer before performing any memory copy operations.
- Consultation4.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-21373 — 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-2026-21373 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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