CVE-2026-71935
Authenticated web-admin buffer overflow in DrayTek VigorSwitch allows DoS or RCE
Is CVE-2026-71935 being exploited?
Not confirmed. CVE-2026-71935 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. EPSS currently estimates a 0.48% probability of exploitation in the next 30 days.
How severe is CVE-2026-71935?
CVE-2026-71935 is rated High with a CVSS score of 8.6. 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-2026-71935?
Not known from our data. No patch reference has been recorded for CVE-2026-71935, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-71935 affect?
CVE-2026-71935 affects DrayTek VigorSwitch series (web management - webBackupAction). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-71935?
Restrict/disable web admin, require VPN, rotate creds; apply vendor patch when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
An authenticated admin via web UI can trigger a stack buffer overflow in webBackupAction to cause DoS or potentially execute arbitrary commands.
Patch when possible
- affected< 3.9.10
- affected< 2.9.10
- affected< 2.9.10
- affected< 2.9.10
- affected< 2.9.10
- affected< 2.9.10
- affected< 2.10.6
- affected< 2.9.10
- affected< 3.9.10
- affected< 3.10.6
- affected< 2.9.10
- affected< 2.9.10
- affected< 2.9.10
- affected< 2.9.10
- affected< 2.9.10
- affected< 2.9.10
- affected< 2.10.6
- affected< 2.9.10
- affected< 3.9.10
- affected< 3.10.6
- affected< 3.10.6
- affected< 2.9.10
- affected< 2.9.10
- affected< 2.10.7
- affected< 2.9.10
- affected< 2.9.10
- affected< 2.9.10
- affected< 2.10.7
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.