How severe is CVE-2023-0856?

CVE-2023-0856 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-2023-0856 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-0856?

CVE-2023-0856 primarily affects Canon Mf642cdw Firmware. In total, 45 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-0856?

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-2023-0856 published?

CVE-2023-0856 was published on 2023-05-11 and last updated on 2026-06-17.

CVE-2023-0856

CVE-2023-0856 is a critical-severity vulnerability in Canon Mf642cdw 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-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (63rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Canon Mf642cdw Firmware
Published: 2023-05-11
Last modified: 2026-06-17

Description

Buffer overflow in IPP sides attribute process of Office / Small Office Multifunction Printers and Laser Printers(*) which may allow an attacker on the network segment to trigger the affected product being unresponsive or to execute arbitrary code. *:Satera LBP660C Series/LBP620C Series/MF740C Series/MF640C Series firmware Ver.11.04 and earlier sold in Japan. Color imageCLASS LBP660C Series/LBP 620C Series/X LBP1127C/MF740C Series/MF640C Series/X MF1127C firmware Ver.11.04 and earlier sold in US. i-SENSYS LBP660C Series/LBP620C Series/MF740C Series/MF640C Series, C1127P, C1127iF, C1127i firmware Ver.11.04 and earlier sold in Europe.

Frequently asked questions

What is CVE-2023-0856?: Buffer overflow in IPP sides attribute process of Office / Small Office Multifunction Printers and Laser Printers(*) which may allow an attacker on the network segment to trigger the affected product being unresponsive or to execute arbitrary code. *:Satera LBP660C Series/LBP620C Series/MF740C Series/MF640C Series firmware Ver.11.04 and earlier sold in Japan. Color imageCLASS LBP660C Series/LBP 620C Series/X LBP1127C/MF740C Series/MF640C Series/X MF1127C firmware Ver.11.04 and earlier sold in US. i-SENSYS LBP660C Series/LBP620C Series/MF740C Series/MF640C Series, C1127P, C1127iF, C1127i firmware Ver.11.04 and earlier sold in Europe.
How severe is CVE-2023-0856?: CVE-2023-0856 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-2023-0856 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-0856?: CVE-2023-0856 primarily affects Canon Mf642cdw Firmware. In total, 45 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-0856?: 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-2023-0856 published?: CVE-2023-0856 was published on 2023-05-11 and last updated on 2026-06-17.

References

Affected products (45)

cpe:2.3:o:canon:mf642cdw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf644cdw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf741cdw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf743cdw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf745cdw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:lbp621c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:lbp622c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:lbp661c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:lbp662c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:lbp664c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf1127c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf262dw_ii_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf264dw_ii_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf267dw_ii_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf269dw_ii_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf269dw_vp_ii_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf272dw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf273dw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf275dw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf641cw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:mf746cdw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:lbp122dw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:lbp1127c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:lbp622cdw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:lbp623cdw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:lbp664cdw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:imageprograf_tc-20_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:imageprograf_tc-20m_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:pixma_g3270_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:pixma_g4270_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:maxify_gx3020_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:maxify_gx4020_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:i-sensys_lbp621cw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:i-sensys_lbp623cdw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:i-sensys_lbp633cdw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:i-sensys_lbp664cx_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:i-sensys_mf641cw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:i-sensys_mf643cdw_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:i-sensys_mf645cx_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:canon:i-sensys_mf742cdw_firmware:*:*:*:*:*:*:*:*

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