CVE-2026-12503
Authenticated symlink allows /etc/passwd writable and root escalation on Loytec devices.
Is CVE-2026-12503 being exploited?
Not confirmed. CVE-2026-12503 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 0.14% probability of exploitation in the next 30 days.
How severe is CVE-2026-12503?
CVE-2026-12503 is rated Critical with a CVSS score of 9.2. 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-2026-12503?
Yes. A fix has been recorded for CVE-2026-12503. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-12503 affect?
CVE-2026-12503 affects Loytec L-INX (LINX-A64) <= 8.4.16, L-GATE, L-ROC, L-IOB, and 3 further products or versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-12503?
Isolate devices, restrict/disable larmapp access, rotate credentials; apply vendor firmware when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated 'larmapp' can exploit a symlink on /etc/lighttpd/ssl/server.pem to make /etc/passwd writable by larmapp group, enabling local root privilege escalation.
Immediate action required
- affected<= 8.4.16
- affected<= 8.4.16
- affected<= 8.4.16
- affected<= 8.4.16
- affected<= 8.4.16
- affected<= 8.4.16
- affected<= 8.4.16
- affected<= 8.4.16
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.