# CVE-2026-63077: JetBrains TeamCity Deserialization of Untrusted Data Vulnerability

- Exploited (CISA KEV): yes, added 2026-08-05, known ransomware use
- Published: 2026-07-27
- CVSS: 9.8 CRITICAL (v3.1)
- EPSS: 93.6% (100th percentile)
- CWE: CWE-502

In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | No public claim | — | — |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2026-09-16 | 51 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### F5

- 2026-09-16 · new · rule 200204092
  > Added: signature 200204092 "JetBrains TeamCity Unauthenticated Remote Code Execution" (Server Side Code Injection, risk High), systems: Java Servlets/JSP. References: CVE-2026-63077.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog

## Our test (measured)

- OWASP Core Rule Set 4.25.0, paranoia level 1, anomaly threshold 5, default CRS settings: partial (1 of 4 requests blocked), template CVE-2026-63077, 2026-11-02
- OWASP Core Rule Set 4.25.0, paranoia level 2, anomaly threshold 5, default CRS settings: partial (1 of 4 requests blocked), template CVE-2026-63077, 2026-11-02

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2026-63077 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2026-63077