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NVD / CVE Program· CNA zephyr

CVE-2026-17052: Missing user-pointer validation in tgpio_pin_read_ts_ec syscall handler allows arbitrary supervisor-memory write from userspace

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.16% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: zephyrproject zephyr 4.3.2, 4.4.2.

Low priority for now. Upgrade to zephyrproject zephyr 4.3.2, 4.4.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

The Time-aware GPIO syscall verification handler z_vrfy_tgpio_pin_read_ts_ec() in drivers/timeaware_gpio/timeaware_gpio_handlers.c validated only the port device object and passed the caller-supplied timestamp and event_count output pointers to the driver without a K_SYSCALL_MEMORY_WRITE() check. The other handlers in the same file (z_vrfy_tgpio_port_get_time(), z_vrfy_tgpio_port_get_cycles_per_second()) already performed that check, so the omission left one syscall unguarded. tgpio_pin_read_ts_ec() is declared __syscall, so with CONFIG_USERSPACE=y an unprivileged user-mode thread that has been granted access to the TGPIO device object can invoke it with arbitrary pointer values. tgpio_intel_read_ts_ec() in drivers/timeaware_gpio/timeaware_gpio_intel.c bounds-checks only the pin index and then unconditionally performs timestamp = ... and event_count = ..., executing two 8-byte stores in supervisor mode at addresses chosen by the user-mode caller. The result is a write-what-where primitive that crosses the userspace/kernel boundary: the target address is fully attacker-chosen and the stored values are the hardware time-capture and event-counter register contents. Corrupting kernel data structures this way can escalate the calling thread to supervisor privilege or crash the system; the device-object permission required is a narrow capability that is not intended to confer any kernel-memory access. The fix adds the two missing K_SYSCALL_MEMORY_WRITE() validations before the driver call. Exposure is narrow in practice. Only builds with CONFIG_USERSPACE=y and CONFIG_TIMEAWARE_GPIO=y compile the affected file, and from v3.6.0 onward the file additionally referenced a relocated header (<zephyr/syscall_handler.h>) and removed Z_SYSCALL_* macros, so such a configuration failed to build until those were repaired after v4.4.0. Downstream trees that locally corrected that breakage, and v3.5.0 builds where it did not exist, are the exposed population.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Sep 21, 2026
Updated
Nov 4, 2026
EPSS
0.1% · 5th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · zephyr
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (zephyr). Independent of NVD's CPE analysis and usually ahead of it.

  • zephyrproject zephyr

    • 3.5.0 and later · before 4.3.2affected · semver
    • 4.4.0 and later · before 4.4.2affected · semver

Same product

zephyrproject: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-4260Potential off-by-one buffer overflow vulnerability in the Zephyr FS subsystem
    40Plan
  • CVE-2021-3625Buffer overflow in Zephyr USB DFU DNLOAD
    40Plan
  • CVE-2020-10071Insufficient publish message length validation in MQTT
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-17051Sep 21, 2026 · Out-of-bounds write in the Intel SEDI IPM driver from an unvalidated inbound doorbell length
    24Monitor
  • ← EarlierCVE-2026-17054Sep 21, 2026 · Out-of-bounds read and permanent loss of Wi-Fi reception in the ESP-hosted SPI driver's frame reassembly
    21Monitor
  • Later →CVE-2026-15890Sep 21, 2026 · AEAD nonce reuse in Zephyr secure_storage ITS default nonce provider due to missing thread synchronization
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
zephyrproject zephyr4.3.2Vendor (CNA)
zephyrproject zephyr4.4.2Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-1321427 days apartStack buffer overflow in OCPP GetConfiguration key parsing
    39Monitor
  • CVE-2026-1678200 days apartdns: memory‑safety issue in the DNS name parser
    39Monitor
  • CVE-2026-7678828 days apartStack out-of-bounds write in the OSDP Control Panel reply parser
    35Monitor
  • CVE-2026-7998232 days apartOut-of-bounds write in the USB Bluetooth HCI transport class when a controller-to-host HCI packet exceeds the bulk endpoint maximum packet size
    35Monitor
  • CVE-2026-1252233 days apartStack buffer overflow in Zephyr hl7800 modem driver parsing network-supplied +CGCONTRDP address fields
    35Monitor
  • CVE-2026-1651144 days apartUnvalidated user pointers in RTIO syscall verifiers allow a user-mode thread to write kernel memory
    35Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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