ZephyrOperating system · Zephyrproject

CVE-2026-5072

MEDIUM · 6.5 CVSS v3.1 Published 2026-05-22
Fix available
A fix is available. Upgrade to after 4.3.0 or later.
See remediation →
70/100
Remediation priority · Elevated
Public exploit No privileges Zero-click Patch available

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
A bitwise shift vulnerability in Zephyr's PTP subsystem allows a remote attacker to cause undefined behavior and potential system crashes. An attacker sends a crafted PTP_MSG_MANAGEMENT message to set an unvalidated negative log_announce_interval value in the port's data set. When a subsequent PTP_MSG_ANNOUNCE message is processed, port_timer_set_timeout_random computes a timeout as NSEC_PER_SEC >> -log_seconds; if the attacker-supplied value is sufficiently negative (e.g., -127), the shift amount exceeds the 64-bit integer width, triggering undefined behavior in C. This can cause a system crash via a compiler-generated illegal instruction trap on some architectures, or produce an erroneous zero timeout leading to resource starvation loops or other logical errors.

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

A detailed technical summary for this CVE is being prepared.

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 data
ZephyrOperating system
Affected:<= 4.3.0

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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

dbcve · scoped
Upgrade available Upgrade to a release after 4.3.0
Vendor patch github.com →
Recommended fix Moderate confidence

Zephyr 4.3.1 or later (the next stable release after 4.3.0 containing the GHSA-3v98-458v-388r fix)

  1. 1. Identify all Zephyr-based products and devices using PTP (Precision Time Protocol) functionality.
  2. 2. Locate the specific Zephyr version in use by checking the West manifest or the project's dependency files (e.g., west.yml, zephyr/module.yml).
  3. 3. If the Zephyr version is <= 4.3.0, plan an upgrade to a version containing the fix for GHSA-3v98-458v-388r.
  4. 4. Pull the latest Zephyr release or the specific version with the security fix applied.
  5. 5. Rebuild the firmware with the updated Zephyr codebase.
  6. 6. Validate the fix by testing PTP functionality with both normal and crafted PTP_MSG_MANAGEMENT messages to confirm the negative log_announce_interval is rejected or handled safely.
  7. 7. Deploy the updated firmware to affected devices.

Generated from the published advisory — verify against the referenced sources before acting.

We can identify the exact fixed release, upgrade, and verify it in staging — typical engagement from $1,600. Get the upgrade done

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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-2026-5072 in production — separate from our analysis above.

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