CVE-2026-21371
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 retrieving output buffer with insufficient size validation.
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 occurs when retrieving an output buffer without proper size validation, potentially allowing an attacker to overwrite adjacent memory regions. This suggests a bounds-checking failure in buffer handling logic.
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 chipset model in the systemCheck system information or device specs to determine if the hardware uses a Snapdragon 8cx, 8cx Gen 2, 8cx Gen 3, 8c, or Wcd9340 chipset. This may be found via /proc/cpuinfo, system firmware tables, or hardware documentation.Affected if The system uses any of the listed chipsets: Snapdragon 8cx (any variant), Snapdragon 8cx Gen 2 5g, Snapdragon 8cx Gen 3, Snapdragon 8c, or Wcd9340.
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Confirm the specific firmware componentDetermine if the firmware running on the device includes the Qualcomm baseband/processing firmware components associated with these chipsets. This may require checking firmware version strings or bootloader information.Affected if The device firmware is the original Qualcomm firmware for the identified chipset (not a third-party or modified firmware).
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Check firmware version if accessibleAttempt to retrieve the firmware version through vendor-specific tools, debug interfaces, or system logs. Compare against any version information available from the vendor.Affected if All versions of the listed firmware are affected per the CVE; if you can confirm the firmware is the original Qualcomm firmware for these platforms, it is considered affected.
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Identify if buffer output operations are in useDetermine if the system performs output buffer retrieval operations, particularly in audio, video, or baseband processing contexts where the Wcd9340 or Snapdragon compute platform firmware handles data buffers.Affected if The system uses the affected firmware components for buffer handling operations.
A system is affected if it uses any Qualcomm Snapdragon 8cx, 8cx Gen 2/3, 8c, or Wcd9340 firmware, as all versions of these firmware components contain the buffer size validation vulnerability.
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 dataImplement rigorous size validation checks before buffer operations and ensure buffer allocations account for maximum expected data sizes.
- Consultation2.0 h
- Implementation8.0 h
- Testing4.0 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 $4,480.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-21371 — 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-2026-21371 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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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