How severe is CVE-2023-39780?

CVE-2023-39780 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which products are affected by CVE-2023-39780?

CVE-2023-39780 affects the following products: asus rt-ax55 firmware.

How do I patch CVE-2023-39780?

No patch has shipped for CVE-2023-39780 yet — track the asus rt-ax55 firmware advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-2023-39780 across my infrastructure?

Inventory every asus rt-ax55 firmware deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

How do I mitigate CVE-2023-39780 if there is no patch (or I can't update yet)?

Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

How does O3 Security protect against CVE-2023-39780?

O3 detects and blocks CVE-2023-39780 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Is CVE-2023-39780 actively exploited in the wild?

Yes. There are 6 known exploit references for CVE-2023-39780, including 6 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2023-39780?

CVE-2023-39780 has an EPSS (Exploit Prediction Scoring System) score of 33.9%, placing it in the 98th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

Is CVE-2023-39780 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2023-39780 (ASUS RT-AX55 Routers OS Command Injection Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2025-06-02. CISA required all US federal civilian agencies to remediate this vulnerability by 2025-06-23. The required action was: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2023-39780?

CVE-2023-39780 is classified as OS Command Injection (CWE-78). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Which products and versions are affected by CVE-2023-39780?

CVE-2023-39780 affects asus rt-ax55 firmware (1 version, e.g. 3.0.0.4.386.51598). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2023-39780 published, and has it been updated?

CVE-2023-39780 was published on September 11, 2023 and was last updated on June 17, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🛡️

CISA KEV · ACTIVELY EXPLOITED

HIGH severity

CVE-2023-39780

HIGH

CVE-2023-39780 is a high-severity (CVSS 8.8) OS Command Injection vulnerability in asus rt-ax55 firmware. It is in CISA's Known Exploited Vulnerabilities catalog (added 2025-06-02) — treat it as actively exploited and patch now. O3 Security detects and blocks CVE-2023-39780 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.

On ASUS RT-AX55 3.0.0.4.386.51598 devices, authenticated attackers can perform OS command injection via the /start_apply.htm qos_bw_rulelist parameter. NOTE: for the similar "token-generated…

Published

Sep 11, 2023

Updated

Jun 17, 2026

Affected

1 product

Patched

See advisory

Exploits

6 known

Exploitation data as of Aug 27, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2025-06-02. Federal agencies were required to remediate by 2025-06-23.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2023-39780.

EPSS Exploitation Probability

via FIRST.org ↗

33.9%probability of exploitation in next 30 days

Moderate Risk0.00%

Lower risk than most CVEs98th percentile — riskier than 98% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2023-39780 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 0 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Description

On ASUS RT-AX55 3.0.0.4.386.51598 devices, authenticated attackers can perform OS command injection via the /start_apply.htm qos_bw_rulelist parameter. NOTE: for the similar "token-generated module" issue, see CVE-2023-41345; for the similar "token-refresh module" issue, see CVE-2023-41346; for the similar "check token module" issue, see CVE-2023-41347; and for the similar "code-authentication module" issue, see CVE-2023-41348.

Affected Products

1 product · 1 configurations

rt-ax55 firmwareasus

1 version

3.0.0.4.386.51598

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.