CVE-2017-12238: Cisco Catalyst 6800 Series Switches VPLS Denial-of-Service Vulnerability
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
A vulnerability in the Virtual Private LAN Service (VPLS) code of Cisco IOS for Cisco Catalyst 6800 Series Switches could allow an unauthenticated, adjacent attacker to cause a denial of service.
CSIRTS triage
- What
- A vulnerability in the VPLS code could allow an unauthenticated attacker to cause a denial of service.
- Who is affected
- Cisco Catalyst 6800 Series Switches with VPLS enabled are affected.
- Urgency
- Immediate remediation is necessary as the vulnerability is actively exploited and rated critical.
- Action
- Update to the latest Cisco IOS version to mitigate this issue.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2017-12238
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2017-12238Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 79% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2017-12238 | coverage & exploitation status | NVD · CVE.org |
Recent advisories for Cisco Catalyst
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- highCisco Catalyst Center Arbitrary File Read Vulnerabilitycisco-psirt · 2026-07-06
- medium[UPDATE] [medium] Cisco Catalyst Center: Vulnerability Allows Information Disclosurecert-bund · 2026-07-03
- unknownNCSC-2026-0218 [1.00] [M/H] Vulnerability fixed in Cisco Catalyst Centerncsc-nl · 2026-07-02
- highCVE-2026-20191: A vulnerability in Cisco Catalyst Center could allow an unauthenticated, remote attacker to re…nvd · 2026-07-01
- criticalexploitedCisco Catalyst SD-WAN Controller Authentication Bypass Vulnerabilitycisco-psirt · 2026-06-16
- highexploitedCisco Catalyst SD-WAN Controller Authentication Bypass Vulnerabilitycisco-psirt · 2026-06-16
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