How severe is CVE-2025-7635?

CVE-2025-7635 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2025-7635 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-7635?

CVE-2025-7635 primarily affects Calix Calix Gigacenter Ont. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-7635?

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-2025-7635 have an EU (EUVD) identifier?

Yes. CVE-2025-7635 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-27466.

When was CVE-2025-7635 published?

CVE-2025-7635 was published on 2025-09-09 and last updated on 2026-06-17.

CVE-2025-7635

CVE-2025-7635 is a high-severity vulnerability in Calix Calix Gigacenter Ont with a CVSS 3.x base score of 7.7. 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-306.

Key facts

Severity: High (CVSS 3.x base score 7.7)
CVSS v4: 8.7
EPSS exploit prediction: 0% (19th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-27466
Weakness: CWE-306
Affected product: Calix Calix Gigacenter Ont
Published: 2025-09-09
Last modified: 2026-06-17

Description

Unauthenticated Telnet access vulnerability in Calix GigaCenter ONT allows root access.This issue affects GigaCenter ONT: 844E, 844G, 844GE, 854GE.

Frequently asked questions

What is CVE-2025-7635?: Unauthenticated Telnet access vulnerability in Calix GigaCenter ONT allows root access.This issue affects GigaCenter ONT: 844E, 844G, 844GE, 854GE.
How severe is CVE-2025-7635?: CVE-2025-7635 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2025-7635 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-7635?: CVE-2025-7635 primarily affects Calix Calix Gigacenter Ont. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-7635?: 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-2025-7635 have an EU (EUVD) identifier?: Yes. CVE-2025-7635 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-27466.
When was CVE-2025-7635 published?: CVE-2025-7635 was published on 2025-09-09 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:calix:calix_gigacenter_ont:*:*:*:*:*:*:*:*
cpe:2.3:a:calix:calix_gigacenter_ont:844e:*:*:*:*:*:*:*
cpe:2.3:a:calix:calix_gigacenter_ont:844g:*:*:*:*:*:*:*
cpe:2.3:a:calix:calix_gigacenter_ont:844ge:*:*:*:*:*:*:*
cpe:2.3:a:calix:calix_gigacenter_ont:854ge:*:*:*:*:*:*:*

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