How severe is CVE-2025-12240?

CVE-2025-12240 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-12240 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-12240?

CVE-2025-12240 affects Totolink A3300r Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-12240?

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.

Does CVE-2025-12240 have an EU (EUVD) identifier?

Yes. CVE-2025-12240 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-36097.

When was CVE-2025-12240 published?

CVE-2025-12240 was published on 2025-10-27 and last updated on 2026-06-17.

CVE-2025-12240

CVE-2025-12240 is a high-severity vulnerability in Totolink A3300r Firmware with a CVSS 3.x base score of 8.8. 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-120.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.0
CVSS v4: 7.4
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-36097
Weakness: CWE-120
Affected product: Totolink A3300r Firmware
Published: 2025-10-27
Last modified: 2026-06-17

Description

A security vulnerability has been detected in TOTOLINK A3300R 17.0.0cu.557_B20221024. This affects the function setDmzCfg of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument ip leads to buffer overflow. It is possible to initiate the attack remotely. The exploit has been disclosed publicly and may be used.

Frequently asked questions

What is CVE-2025-12240?: A security vulnerability has been detected in TOTOLINK A3300R 17.0.0cu.557_B20221024. This affects the function setDmzCfg of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument ip leads to buffer overflow. It is possible to initiate the attack remotely. The exploit has been disclosed publicly and may be used.
How severe is CVE-2025-12240?: CVE-2025-12240 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-12240 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-12240?: CVE-2025-12240 affects Totolink A3300r Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-12240?: 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.
Does CVE-2025-12240 have an EU (EUVD) identifier?: Yes. CVE-2025-12240 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-36097.
When was CVE-2025-12240 published?: CVE-2025-12240 was published on 2025-10-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:totolink:a3300r_firmware:17.0.0cu.557_b20221024:*:*:*:*:*:*:*

More vulnerabilities in Totolink A3300r Firmware

CVE-2026-31181 — Critical (CVSS 9.8): An issue was discovered in ToToLink A3300R firmware v17.0.0cu.557_B20221024 allowing attackers to execute arbitrary…
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