Impacts Arista network device management interfaces used across enterprises; exploitation can compromise admin sessions and modify network configs, risking broad operational disruption.
CVE-2026-101157
Stored XSS in Arista web management UI enabling admin-session compromise.
Is CVE-2026-101157 being exploited?
Not confirmed. CVE-2026-101157 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2026-101157?
CVE-2026-101157 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-101157?
Yes. A fix has been recorded for CVE-2026-101157. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-101157 affect?
CVE-2026-101157 affects Arista network devices (web management interfaces). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-101157?
Restrict UI access, apply vendor mitigations/patches ASAP, rotate creds, monitor logs.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Adjacent-network stored XSS lets attackers execute script in admin browsers, compromise sessions, access data, change configs, or disrupt services.
Immediate action required
- affected>= 2021.2.0 and <= 2026.2.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.