# CVE-2023-26258: CVE-2023-26258

- Exploited (CISA KEV): no
- Published: 2023-07-03
- CVSS: not scored
- EPSS: 40.0% (99th percentile)

Arcserve UDP through 9.0.6034 allows authentication bypass. The method getVersionInfo at WebServiceImpl/services/FlashServiceImpl leaks the AuthUUID token. This token can be used at /WebServiceImpl/services/VirtualStandbyServiceImpl to obtain a valid session. This session can be used to execute any task as administrator.

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

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Before feed history | — | — |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | Before feed history | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2026-01-20 | 932 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### F5

- 2026-01-20 · new · rule 200013162
  > Added: signature 200013162 "Arcserve UDP Authentication Bypass (2)" (Authentication/Authorization Attacks, risk High), systems: Other Web Server. References: CVE-2023-26258.
  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: passed (0 of 3 requests blocked), template CVE-2023-26258, 2026-11-02
- OWASP Core Rule Set 4.25.0, paranoia level 2, anomaly threshold 5, default CRS settings: passed (0 of 3 requests blocked), template CVE-2023-26258, 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-2023-26258 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2023-26258