How severe is CVE-2021-3510?

CVE-2021-3510 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-3510 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3510?

CVE-2021-3510 primarily affects Zephyrproject Zephyr. In total, 22 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-3510?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-3510 published?

CVE-2021-3510 was published on 2021-10-05 and last updated on 2026-06-17.

CVE-2021-3510

CVE-2021-3510 is a high-severity vulnerability in Zephyrproject Zephyr with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-588.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-588
Affected product: Zephyrproject Zephyr
Published: 2021-10-05
Last modified: 2026-06-17

Description

Zephyr JSON decoder incorrectly decodes array of array. Zephyr versions >= >1.14.0, >= >2.5.0 contain Attempt to Access Child of a Non-structure Pointer (CWE-588). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-289f-7mw3-2qf4

Frequently asked questions

What is CVE-2021-3510?: Zephyr JSON decoder incorrectly decodes array of array. Zephyr versions >= >1.14.0, >= >2.5.0 contain Attempt to Access Child of a Non-structure Pointer (CWE-588). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-289f-7mw3-2qf4
How severe is CVE-2021-3510?: CVE-2021-3510 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-3510 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3510?: CVE-2021-3510 primarily affects Zephyrproject Zephyr. In total, 22 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-3510?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-3510 published?: CVE-2021-3510 was published on 2021-10-05 and last updated on 2026-06-17.

References

http://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-289f-7mw3-2qf4

Affected products (22)

cpe:2.3:o:zephyrproject:zephyr:1.14.0:-:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:1.14.0:rc1:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:1.14.0:rc2:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:1.14.0:rc3:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:1.14.1:-:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:1.14.1:rc1:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:1.14.1:rc2:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:1.14.1:rc3:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:1.14.2:*:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:1.14.3:rc1:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:1.14.3:rc2:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:2.5.0:-:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:2.5.0:rc1:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:2.5.0:rc2:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:2.5.0:rc3:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:2.5.0:rc4:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:2.5.1:rc1:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:2.6.0:-:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:2.6.0:rc1:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:2.6.0:rc2:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:2.6.0:rc3:*:*:*:*:*:*
cpe:2.3:o:zephyrproject:zephyr:2.6.1:rc1:*:*:*:*:*:*

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