How severe is CVE-2021-3942?

CVE-2021-3942 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-3942 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3942?

CVE-2021-3942 primarily affects Hp Color Laserjet Cm4540 Mfp Cc419a Firmware. In total, 2723 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-3942?

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

When was CVE-2021-3942 published?

CVE-2021-3942 was published on 2022-12-12 and last updated on 2026-06-17.

CVE-2021-3942

CVE-2021-3942 is a critical-severity vulnerability in Hp Color Laserjet Cm4540 Mfp Cc419a Firmware with a CVSS 3.x base score of 9.8. 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-119.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (69th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Hp Color Laserjet Cm4540 Mfp Cc419a Firmware
Published: 2022-12-12
Last modified: 2026-06-17

Description

Certain HP Print products and Digital Sending products may be vulnerable to potential remote code execution and buffer overflow with use of Link-Local Multicast Name Resolution or LLMNR.

Frequently asked questions

What is CVE-2021-3942?: Certain HP Print products and Digital Sending products may be vulnerable to potential remote code execution and buffer overflow with use of Link-Local Multicast Name Resolution or LLMNR.
How severe is CVE-2021-3942?: CVE-2021-3942 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-3942 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3942?: CVE-2021-3942 primarily affects Hp Color Laserjet Cm4540 Mfp Cc419a Firmware. In total, 2723 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-3942?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-3942 published?: CVE-2021-3942 was published on 2022-12-12 and last updated on 2026-06-17.

References

https://support.hp.com/us-en/document/ish_5948778-5949142-16/hpsbpi03780

Affected products (2723)

cpe:2.3:o:hp:color_laserjet_cm4540_mfp_cc419a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_cm4540_mfp_cc420a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_cm4540_mfp_cc421a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_cm5525_mfp_ce707a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_cm5525_mfp_ce708a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_cm5525_mfp_ce709a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_m578_mfp_7zu85a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_m578_mfp_7zu86a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_m578_mfp_7zu87a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_m578_mfp_7zu88a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_enterprise_flow_mfp_m880z_d7p70a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_enterprise_flow_mfp_m880z_a2w75a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_enterprise_flow_mfp_m880z_a2w76a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_enterprise_flow_mfp_m880z_d7p71a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_enterprise_flow_mfp_m880z_l3u51a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_enterprise_flow_mfp_m880z_l3u52a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_managed_flow_mfp_m880zm_d7p70a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_managed_flow_mfp_m880zm_a2w75a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_managed_flow_mfp_m880zm_a2w76a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_managed_flow_mfp_m880zm_d7p71a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_managed_flow_mfp_m880zm_l3u51a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_managed_flow_mfp_m880zm_l3u52a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_m455_39z95a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_m552_b5l23a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_enterprise_m553_b5l24a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_enterprise_m553_b5l25a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_enterprise_m553_b5l26a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_enterprise_m553_b5l27a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_enterprise_m553_b5l38a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_enterprise_m553_b5l39a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_managed_m553_b5l24a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_managed_m553_b5l25a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_managed_m553_b5l26a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_managed_m553_b5l27a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:color_laserjet_managed_m553_b5l38a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:designjet_t2600_36\"_mfp_3ek15a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:designjet_t2600_36\"_mfp_3ek15b_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:designjet_t2600_36\"_mfp_3ek15k_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:designjet_t2600_36\"_mfp_3xb77a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hp:designjet_t2600_36\"_mfp_3xb78a_firmware:*:*:*:*:*:*:*:*

Other CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities

CVE-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…
CVE-2025-1866 — Critical (CVSS 10.0): Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows…
CVE-2022-27625 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
CVE-2022-27624 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
CVE-2020-11896 — Critical (CVSS 10.0): The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

Browse all CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities →