Auth bypass in Calix Gigacenter Ont
CVE-2025-7635
Unauthenticated Telnet access vulnerability in Calix GigaCenter ONT allows root access.This issue affects GigaCenter ONT: 844E, 844G, 844GE, 854GE.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (26.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 26.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Calix Gigacenter Ont — versions 844e, 844g, 844ge
- Calix Gigacenter Ont — versions 844E, 844G, 844GE
Weakness classification (CWE)
Public proof-of-concept exploits
References
- fluidattacks.com/advisories/sal (Exploit, Third Party Advisory, Mitigation, third-party-advisory)
- www.calix.com (related, Product, product)
- revers3everything.com/calix-case-five-0-days-five-cves/ (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2025-7635?
- CVE-2025-7635 is a high-severity vulnerability in Calix Gigacenter Ont, classified under Missing Authentication for Critical Function. CVSS score: 7.7/10. Published 2025-09-09.
- How severe is CVE-2025-7635?
- High severity. CVSS v3 base score is 7.7 out of 10.
- Is CVE-2025-7635 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.