How severe is CVE-2023-26921?

CVE-2023-26921 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-2023-26921 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-26921?

CVE-2023-26921 affects Quectel Ag550qcn Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-26921?

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-2023-26921 published?

CVE-2023-26921 was published on 2023-04-04 and last updated on 2026-06-17.

CVE-2023-26921

CVE-2023-26921 is a critical-severity vulnerability in Quectel Ag550qcn 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-78.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Quectel Ag550qcn Firmware
Published: 2023-04-04
Last modified: 2026-06-17

Description

OS Command Injection vulnerability in quectel AG550QCN allows attackers to execute arbitrary commands via ql_atfwd.

Frequently asked questions

What is CVE-2023-26921?: OS Command Injection vulnerability in quectel AG550QCN allows attackers to execute arbitrary commands via ql_atfwd.
How severe is CVE-2023-26921?: CVE-2023-26921 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-2023-26921 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-26921?: CVE-2023-26921 affects Quectel Ag550qcn Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-26921?: 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-2023-26921 published?: CVE-2023-26921 was published on 2023-04-04 and last updated on 2026-06-17.

References

https://github.com/closethe/AG550QCN_CommandInjection_ql_atfwd/blob/main/README.md

Affected products (1)

cpe:2.3:o:quectel:ag550qcn_firmware:-:*:*:*:*:*:*:*

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