VulnerabilityPublished 14 Mar 2026Updated 15 Oct 2026

CVE-2026-0849: zephyrproject-rtos Zephyr · Classic Buffer Overflow

Affects zephyrproject-rtos ZephyrSource CVE Database V5

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Not known to be exploited · CVSS 3.8 Low : upgrade to 4.4.0 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

3.8Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.4.0

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

Attack Vector: Physical
Attack Complexity: High
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Physical: The attack requires the attacker to physically touch or manipulate the vulnerable component. Physical interaction may be brief or persistent.
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 14 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade zephyrproject-rtos Zephyr to 4.4.0.

Affected software

Product	Affected	Fixed in
zephyrproject-rtosZephyr	Affected <4.4.0	Fixed in 4.4.0
GitHubzephyrproject-rtos/zephyr`pkg:github/zephyrproject-rtos/zephyr`Other threats	Affected *	Fixed in–
GitHubZephyr`pkg:github/Zephyr`Other threats	Affected <4.4.0	Fixed in 4.4.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2026-0849, organizations should monitor Zephyr project updates and apply security patches promptly once released. If you cannot patch yet, restrict physical and network access to device buses handling ATAES132A communications to trusted personnel and systems only. Implement hardware-level protections such as bus encryption or authentication to prevent unauthorized device or bus access. Conduct thorough code audits and fuzz testing on the crypto driver to identify and remediate similar input validation issues. Employ runtime protections like stack canaries and address space layout randomization (ASLR) where supported by the embedded platform. Additionally, segment network and device access to minimize the attack surface and detect anomalous bus traffic indicative of exploitation attempts. Finally, maintain an inventory of devices running vulnerable Zephyr versions to prioritize remediation efforts.

Description

Malformed ATAES132A responses with an oversized length field overflow a 52-byte stack buffer in the Zephyr crypto driver, allowing a compromised device or bus attacker to corrupt kernel memory and potentially hijack execution.

Impact

The primary impact of CVE-2026-0849 is the potential for kernel memory corruption leading to arbitrary code execution within the Zephyr RTOS environment. This can undermine the integrity of embedded and IoT devices running Zephyr, potentially allowing attackers to escalate privileges, bypass security controls, or cause denial of service through system crashes. Confidentiality may be affected if the attacker can manipulate cryptographic operations or extract sensitive data. However, the requirement for physical or bus-level access limits the scope of exploitation, reducing the risk of widespread remote attacks. Organizations deploying Zephyr in critical infrastructure, industrial control systems, or consumer IoT devices may face operational disruptions or security breaches if this vulnerability is exploited. The lack of known exploits and the low CVSS score suggest a limited immediate threat, but the potential for kernel-level compromise warrants attention.

References

github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-ff4p-3ggg-prp6 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 22 Mar 2026, 00:27 UTC

Technical details

References

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