Known exploited · Mirasvit

CVE-2026-45247: Mirasvit Full Page Cache Warmer Deserialization of Untrusted Data Vulnerability

What it is

Mirasvit Full Page Cache Warmer contains a deserialization of untrusted data vulnerability that could allow unauthenticated attackers to achieve remote code execution by supplying a crafted serialized PHP object in the CacheWarmer cookie.

Added June 3, 2026Due June 6, 2026CISA KEV catalog 2026.10.01

Vendor
Mirasvit
Product
Mirasvit Full Page Cache Warmer
Added to KEV
June 3, 2026
CISA due date
June 6, 2026
Ransomware use
Unknown

What CISA requires

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Forensic triage

No

What to do now

  1. Find every instance of Mirasvit Full Page Cache Warmer you run, including the forgotten ones, and check its version against the vendor advisory.
  2. Apply the vendor's fix or mitigation, before June 6, 2026 if you are bound by CISA's deadline, sooner if it faces the internet.
  3. Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
  4. Until every instance is patched, block the attack at the edge: a WAF in blocking mode stops Java deserialization payloads.

References

CVE-2026-45247 in the National Vulnerability Database

The Dome

Block it at the edge while you patch

The Dome's WAF runs the OWASP Core Rule Set in blocking mode and stops Java deserialization payloads before they reach your application.

See the Dome

T Academy

Train the engineers who fix it

Security engineering on real hosts in the browser, every objective checked on the machine. The first two lessons of Linux 1 are free.

Start free

Source: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.