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CVE.org (no NVD analysis yet)· CNA zephyr

CVE-2026-18418: Out-of-bounds read when the zbus proxy agent IPC backend logs a rejected peer frame's channel name

LowCVSS 3.4 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 13/100)

  • 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: 0.10% (FIRST EPSS).
  • Someone with local access to the system can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: zephyrproject zephyr 4.4.2.

Low priority for now. Upgrade to zephyrproject zephyr 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 zbus proxy agent IPC backend in subsys/zbus/proxy_agent/zbus_proxy_agent_ipc.c logged the channel name of a rejected inter-domain frame with a plain %s conversion. The frame type struct zbus_proxy_msg carries a fixed-size channel_name[] array as its last member, and nothing in the transport guarantees the array is NUL-terminated. The only code that verifies termination is zbus_proxy_agent_receive_cb() in subsys/zbus/proxy_agent/zbus_proxy_agent.c, which rejects the frame in precisely those cases — so the warning printed a non-terminated buffer exactly on the error paths where the name had been found invalid (or, for an invalid message_size, had not been inspected at all). Any peer domain able to place a frame of sizeof(struct zbus_proxy_msg) bytes on the bound ipc_service endpoint can trigger it, by sending a frame with an out-of-range message_size or with channel_name[] containing no NUL byte. Reaching the code requires CONFIG_ZBUS_PROXY_AGENT_IPC and logging built at warning level or above (the default), and requires control over the firmware of the peer domain — typically a second core on the same SoC. The resulting strlen() inside the log packager walks past the end of the frame object until it finds a zero byte. With the icmsg backend the frame lives in a stack buffer of the IPC work-queue thread, so bytes of that thread's stack are rendered into the log message; with the rpmsg backends the scan continues through the shared vring memory. Impact is bounded to disclosure of a small amount of adjacent memory into the receiving domain's log sink, plus a possible fatal fault if the scan leaves a mapped region; the log packager's own -ENOSPC bound prevents the overrun from becoming a write. The fix bounds the conversion with %.*s and MIN(msg->channel_name_len, sizeof(msg->channel_name)).

Published
Oct 11, 2026
Updated
Oct 15, 2026
EPSS
0.1% · 1th percentile

Report tools

JSON

Action score

13

Monitor

Low priority for now.

CVSS
13 / 40 · 3.4 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · zephyr
3.4
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 exploit code appears or is weaponized
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Noroxi analysis

What does it mean in your environment?

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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

    • 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-2026-19574Oct 9, 2026 · ARM64 MMU can assign an in-use ASID to a new memory domain, breaking user-mode memory isolation
    28Monitor
  • ← EarlierCVE-2026-19575Oct 9, 2026 · Type confusion in the device_deinit system call allows user-mode threads to execute arbitrary kernel code
    31Monitor
  • Later →CVE-2026-19576Oct 11, 2026 · Stack out-of-bounds write in the Goodix GT911 touch controller driver from an unvalidated device-reported touch point count
    27Monitor

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 zephyr4.4.2Vendor (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.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 13, 2026+33 d
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.

Variant candidates

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

  • CVE-2026-1067289 days apartUnterminated URI buffer causes out-of-bounds read in LwM2M firmware pull (Package URI)
    36Monitor
  • CVE-2026-1067388 days apartOut-of-bounds write in ADIN2111/ADIN1110 OA SPI Ethernet RX frame reassembly
    35Monitor
  • CVE-2026-1084870 days apartOut-of-bounds read in Zephyr OCPP 1.6 RPC message parser (parse_rpc_msg)
    34Monitor
  • CVE-2026-7768530 days apartBluetooth Classic RFCOMM: integer underflow in the MCC TEST command handler leads to out-of-bounds read disclosed to the peer and out-of-bounds write
    33Monitor
  • CVE-2026-9263103 days apartOut-of-bounds read in Bluetooth Controller ISOAL framed RX reassembly leaks adjacent memory into host HCI ISO packets
    32Monitor
  • CVE-2026-8704124 days apartInverted memory-permission check in the RTIO syscall verifier allows a user-mode thread to read and write arbitrary kernel memory
    31Monitor

Not on record for this CVE: researcher credit · public bounty program.

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • Administrator privileges are required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

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

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.

ATT&CK techniques

—

Change log

  1. SSVC exploitation— → none
  2. Exploit maturity— → none
  3. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

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

All records