CVE-2026-42485
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 · uneditedAGL agl-service-can-low-level contains a stack buffer overflow in the uds-c library. The send_diagnostic_request function in uds.c allocates a 6-byte stack buffer (MAX_DIAGNOSTIC_PAYLOAD_SIZE=6) but copies up to 7 bytes (MAX_UDS_REQUEST_PAYLOAD_LENGTH=7) via memcpy at an offset of 1+pid_length (2-3 bytes), resulting in 1-4 bytes of controlled stack overflow. The payload_length field (uint8_t) has no bounds check against the destination buffer. On 32-bit ARM automotive ECUs without stack canaries, this can lead to return address overwrite and RCE.
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 confidenceStack buffer overflow in agl-service-can-low-level's send_diagnostic_request function where a 6-byte stack buffer (MAX_DIAGNOSTIC_PAYLOAD_SIZE) receives up to 7 bytes (MAX_UDS_REQUEST_PAYLOAD_LENGTH) via memcpy at offset 1+pid_length. The uint8_t payload_length field lacks bounds validation, allowing 1-4 bytes of controlled overflow that can overwrite the return address on 32-bit ARM ECUs lacking stack canaries, leading to RCE.
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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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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Determine if agl-service-can-low-level is presentSearch for the agl-service-can-low-level package or binary in the system (e.g., dpkg -l, rpm -qa, or find / -name '*can-low-level*')Affected if The package or binary is found on the system
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Identify the installed version of agl-service-can-low-levelRun package manager query (dpkg -s, rpm -qi) or check binary version string if availableAffected if Version cannot be determined or falls within an affected range compared to the fix version
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Verify the send_diagnostic_request function exists in the binaryUse objdump, nm, or strings to locate the send_diagnostic_request symbol in the binaryAffected if The function is present, indicating the vulnerable code path exists
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Confirm target is 32-bit ARM ECU without stack canariesCheck system architecture (uname -m, file on binary) and examine binary for stack canary symbols (e.g., __stack_chk_fail) or compile flagsAffected if Running on 32-bit ARM without stack canaries enabled in the binary; on 64-bit or canary-protected builds the specific return-address overwrite may not apply
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Check if diagnostic request handling is enabledInspect configuration files or runtime settings for CAN diagnostic feature flags that enable send_diagnostic_requestAffected if Diagnostic request handling is enabled and accepts UDS payloads from untrusted CAN sources
User is affected if agl-service-can-low-level is installed with the vulnerable send_diagnostic_request function on a 32-bit ARM ECU lacking stack canaries, and diagnostic request handling is enabled to accept external CAN payloads.
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 bounds checking to validate payload_length against MAX_DIAGNOSTIC_PAYLOAD_SIZE before memcpy, and ensure destination buffer is sized to accommodate the maximum expected payload with appropriate margin.
- Consultation2.0 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 $4,096.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-42485 — 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-2026-42485 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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