CVE-2026-52539
Hardcoded JWT secret in Outstatic CMS allows forging of admin session tokens.
Is CVE-2026-52539 being exploited?
Not confirmed. CVE-2026-52539 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 0.30% probability of exploitation in the next 30 days.
How severe is CVE-2026-52539?
CVE-2026-52539 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-2026-52539?
Not known from our data. No patch reference has been recorded for CVE-2026-52539, 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-2026-52539 affect?
CVE-2026-52539 affects Outstatic CMS <= 2.1.9, Self-hosted Outstatic instances using default OST_TOKEN_SECRET. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-52539?
Set a unique OST_TOKEN_SECRET, revoke/rotate sessions, and upgrade to vendor patched release when available.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated attackers can forge JWTs to gain full administrative access, modify content, takeover accounts, and enable further attacks.
Immediate action required