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TI-2025-19960 Aliases CVE-2025-27090GHSA-fh4v-v779-4g2w

Server-Side Request Forgery (SSRF) in sliver teamserver

Priority HIGH 70CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Information disclosure
Confidentiality · integrity · availability
Low · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-918 and the CVSS impact.

Summary

Sliver is an open source cross-platform adversary emulation/red team framework, it can be used by organizations of all sizes to perform security testing. The reverse port forwarding in sliver teamserver allows the implant to open a reverse tunnel on the sliver teamserver without verifying if the operator instructed the implant to do so. The only impact that has been shown is the exposure of the server's IP address to a third party. This issue has been addressed in version 1.5.43 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00631 50th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed sliver (BishopFox): 1.5.43github.com/bishopfox/sliver (Go): 1.5.43

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
BishopFoxsliver1.5.26 to before 1.5.431.5.43Patch availableCNA
—github.com/bishopfox/sliver (Go)1.5.26 to before 1.5.431.5.43Patch availableGHSA-fh4v-v779-4g2w
  • sliver VendorBishopFox Affected 1.5.26 to before 1.5.43 Fixed in 1.5.43 Patch available CNA
  • github.com/bishopfox/sliver (Go) Vendor— Affected 1.5.26 to before 1.5.43 Fixed in 1.5.43 Patch available GHSA-fh4v-v779-4g2w

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:bishopfox:sliver:*:*:*:*:*:*:*:*1.5.26 to before 1.5.43VulnerableBishopFox
  • cpe:2.3:a:bishopfox:sliver:*:*:*:*:*:*:*:* Versions 1.5.26 to before 1.5.43 Vulnerable ·BishopFox

Remediation

  • Fix · CNA sliver (BishopFox) Fixed in 1.5.43
  • Fix · GHSA-fh4v-v779-4g2w github.com/bishopfox/sliver (Go) Fixed in 1.5.43 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-27090
  2. 2026-10-03 Alias added: GHSA-fh4v-v779-4g2w
  3. 2026-10-27 EPSS moved to the 50th–90th percentile

References

Exploit 1

Patch 2

Advisory 1

Other 1

  • TI-2023-17391 Sliver from v1.5.x to v1.5.39 has an improper cryptographic implementation, which allows… CVSS 3.1HIGH 8.1
  • TI-2026-26522 Sliver One-Click Remote Access: Insecure CORS & Unauthenticated MCP Interface CVSS 4.0MEDIUM 5.9
  • TI-2026-25389 Sliver Vulnerable to Authenticated OOM via Memory Exhaustion in mTLS/WireGuard Transports CVSS 4.0MEDIUM 5.7
  • TI-2026-23367 Sliver: Authenticated Nil-Pointer Dereference in Handlers CVSS 4.0LOW 2.1
  • TI-2026-20855 Sliver has a DNS C2 OTP Bypass Allows Unauthenticated Session Flooding and Denial of Service CVSS 3.1HIGH 7.5
  • TI-2026-20827 Website Path Traversal / Arbitrary File Read (Authenticated) in Sliver CVSS 3.1MEDIUM 6.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences