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CVE-2026-77622— Sliver: Unauthenticated Memory Exhaustion Denial of Service in Sliver HTTP(S) Listener PNG Decoder

Quick assessment

Affected
BishopFox sliver
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Sliver 是一个命令与控制（C2）框架。在 1.7.6 版本之前，使用 PNG 编码器的 HTTP(S) 监听器在 中接受由攻击者控制的 PNG 图像尺寸，且未实施有效的解码后尺寸或像素数量限制；同时， 中实现的监听器随机数（nonce）空间过小，可被远程遍历搜索。未认证的攻击者一旦识别出有效的随机数，即可向 提交高度压缩的图像；该图像在 过程中会急剧膨胀，耗尽服务器内存，导致服务完全不可用（拒绝服务）。此漏洞已在 1.7.6 版本中修复。

CVSS 8.2 · High
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I. Basic Information for CVE-2026-77622

Vulnerability Information
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Vulnerability Title
Sliver: Unauthenticated Memory Exhaustion Denial of Service in Sliver HTTP(S) Listener PNG Decoder
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
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
Source: CVE Program / CVE List V5
Vulnerability Type
不加限制或调节的资源分配
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
BishopFox sliver < 1.7.6 -

II. Public POCs for CVE-2026-77622

# POC Description Source Link Shenlong Link
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III. Intelligence Information for CVE-2026-77622

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Other References for CVE-2026-77622 (3)

IV. Related Vulnerabilities

Same product: sliver
Same vendor: BishopFox
Same weakness: CWE-770