CVE-2026-38426
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 · uneditedBuffer Overflow vulnerability in arendst Tasmota v.15.3.0.3 and before allows a remote attacker to execute arbitrary code via the xdrv_10_scripter.ino, fetch_jpg(), jpg_task.boundary[40], strcpy() function.
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 confidenceA buffer overflow vulnerability exists in Tasmota firmware versions 15.3.0.3 and earlier in the xdrv_10_scripter.ino component. The flaw is in the fetch_jpg() function where the jpg_task.boundary[40] buffer is populated using the unsafe strcpy() function without bounds checking, allowing a remote attacker to overflow the 40-byte buffer and execute arbitrary code.
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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
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 Tasmota firmware versionAccess the device web interface and navigate to Main Configuration > Information, or publish a raw MQTT message to cmnd/%topic%/Status with payload 2 to retrieve the firmware versionAffected if The displayed version is 15.3.0.3 or earlier
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Verify scripter driver is enabledIn the Tasmota web interface, check if the Scripter menu option is present under Configuration, or look for "Scripter" in the driver information shown on the Information pageAffected if The Scripter driver is loaded and visible in the web interface or driver list
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Confirm JPEG streaming functionality is in useCheck if the device has a camera module configured or if the fetch_jpg function would be invoked. This can be verified by checking the module type in Configuration > Configure Module and confirming a camera interface is selected, or by checking for JPEG-related commands in the consoleAffected if The device has a camera module configured and JPEG streaming is actively used or available
You are affected if your Tasmota firmware version is 15.3.0.3 or earlier, the scripter driver is enabled, and the device has JPEG/camera functionality configured that would invoke the vulnerable fetch_jpg() function.
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 dataUpgrade Tasmota firmware to a version newer than 15.3.0.3. If patching is not immediately possible, implement network segmentation to limit exposure of affected devices and disable the scripter functionality if not required.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-38426 — 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-2026-38426 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
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- Version or environment caveats, and links to real fixes
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