CVE-2026-18753
Embedded static RSA private key in device firmware allows HTTPS decryption and spoofing.
Is CVE-2026-18753 being exploited?
Not confirmed. CVE-2026-18753 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 0.31% probability of exploitation in the next 30 days.
How severe is CVE-2026-18753?
CVE-2026-18753 is rated Critical with a CVSS score of 9.1. 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-2026-18753?
Not known from our data. No patch reference has been recorded for CVE-2026-18753, 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-2026-18753 affect?
CVE-2026-18753 affects Embedded devices using Lighttpd TLS, IoT gateways, CPE routers, Network appliances, and 1 further product or version. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-18753?
Revoke/rotate TLS keys and certs; replace embedded keys; apply vendor firmware updates ASAP.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Attackers with the key can decrypt TLS traffic, perform passive interception, and impersonate the server for MITM and traffic decryption.
Immediate action required
- affectedV2.07
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.