CVE-2026-77622

Sliver: Unauthenticated Memory Exhaustion Denial of Service in Sliver HTTP(S) Listener PNG Decoder

Published Nov 5, 2026 CVSS 4.0 · 8.2 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-663m-7x7m-g4fw Sliver: Unauthenticated Memory Exhaustion Denial of Service in Sliver HTTP(S) Listener PNG Decoder
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Bishopfox
Bishopfox sliver
Vendors & Products Bishopfox
Bishopfox sliver
Type Values Removed Values Added
Description 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.
Title Sliver: Unauthenticated Memory Exhaustion Denial of Service in Sliver HTTP(S) Listener PNG Decoder
Weaknesses CWE-770
References
Metrics cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 9, 2026, 5:42 PM
Reserved
Aug 20, 2026, 8:52 PM
Status
Awaiting Analysis
Published
Nov 5, 2026, 9:18 PM
Modified
Nov 12, 2026, 10:18 PM