TI-2026-85667 Aliases CVE-2026-77622

Memory exhaustion in Sliver HTTP(S) listener PNG decoder

LOW 36CWE-770Published 2026-11-05 · Updated 2026-11-05

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: High
Attack requirements: Present
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-770.

Summary

Sliver before 1.7.6, including the Go module github.com/BishopFox/sliver, has a flaw in its HTTP(S) listener PNG decoder. The decoder accepts attacker-controlled PNG dimensions without an effective decoded size or pixel limit, which is a missing resource limit (CWE-770). An unauthenticated remote attacker who finds a valid listener nonce, which can be searched remotely because the nonce space is small, can send a highly compressed image that expands in memory and exhausts server memory, causing a complete loss of availability.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

Description from the CNA

Sliver is a command and control framework. Prior to 1.7.6, an HTTP(S) listener using the PNG encoder accepts attacker-controlled PNG dimensions without an effective decoded-size or pixel limit in util/encoders/images.go, while the listener nonce space implemented in server/encoders/encoders.go is small enough to search remotely. An unauthenticated attacker who identifies a valid nonce can submit a highly compressed image to PNGEncoder.Decode, where it expands during png.Decode, exhausting server memory and causing a complete loss of availability. This vulnerability is fixed in 1.7.6.

Why it matters now

EPSS 0.00535 45th percentileScored 2026-11-07

Fix Fixed sliver (BishopFox): 1.7.6github.com/BishopFox/sliver (Go): 1.7.6

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
BishopFox	sliver	before 1.7.6	1.7.6	Patch available	CNA
—	github.com/BishopFox/sliver (Go)	before 1.7.6	1.7.6	Patch available	GHSA-663m-7x7m-g4fw

sliver VendorBishopFox Affected before 1.7.6 Fixed in 1.7.6 Patch available CNA
github.com/BishopFox/sliver (Go) Vendor— Affected before 1.7.6 Fixed in 1.7.6 Patch available GHSA-663m-7x7m-g4fw

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:bishopfox:sliver::::::::	—	—	BishopFox

cpe:2.3:a:bishopfox:sliver:*:*:*:*:*:*:*:* Versions — — ·BishopFox

Remediation

Update Sliver to version 1.7.6, which fixes the sliver product and the github.com/BishopFox/sliver Go module.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

Fix · CNA sliver (BishopFox) Fixed in 1.7.6
Fix · GHSA-663m-7x7m-g4fw github.com/BishopFox/sliver (Go) Fixed in 1.7.6 Advisory →

Timeline

2026-11-05 Threatist record created from CVE-2026-77622
2026-11-07 Priority changed: MEDIUM → LOW

References

Other 4

TI-2025-19960 Server-Side Request Forgery (SSRF) in sliver teamserver CVSS 4.0MEDIUM 6.9
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-2024-27463 BishopFox Sliver Authenticated Remote Code Execution CVSS 3.1HIGH 7.2
TI-2026-65413 Sliver 1.7.7 Denial of Service via PE Parser Slice Bounds in Operator RPC CVSS 4.0MEDIUM 6.8
TI-2025-19963 Sliver does not restricted traffic between Wireguard clients. CVSS 3.1MEDIUM 6.3
TI-2026-26522 Sliver One-Click Remote Access: Insecure CORS & Unauthenticated MCP Interface CVSS 4.0MEDIUM 5.9

See all 11 →

Sources

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