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CVE-2026-116591— compress zstd: Panic on two-block frames

Quick assessment

Affected
klauspost compress
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.

包提供了多种压缩算法。在版本 1.20.2 之前，当 的 及流式解码路径处理一个精心构造的双块帧时，若该帧在调用 时包含一个值为 32768 的 FSE 归一化计数，而 将其以 类型存储为 -32768，则可能引发 panic。这种计数值的回绕（wrap-around）使得 保留了来自前一个块的陈旧 解码表状态；随后 基于该状态推导出越界的状态值，并访问超出表范围的索引，而非返回解码错误。该漏洞需要两个块配合：第一个块用于保留陈旧状态，第二个块则复用该状态，从而允许不受信任的 输入导致应用程序崩溃。此问题已在版本

CVSS 8.7 · High

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application
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I. Basic Information for CVE-2026-116591

Vulnerability Information
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Vulnerability Title
compress zstd: Panic on two-block frames
Source: CVE Program / CVE List V5
Vulnerability Description
compress provides various compression algorithms. Prior to 1.20.2, the zstd DecodeAll and streaming decoder paths can panic when a crafted two-block frame reaches huff0.ReadTable with an FSE normalized count of 32768 that readNCount stores in int16 as -32768. The wrapped count allows buildDtable to retain stale fse.Scratch decode-table state from the prior block, and nextFast then derives an out-of-range state and indexes beyond the table instead of returning a decode error. Both blocks are required to preserve and then reuse the stale state, allowing untrusted zstd input to crash an application. This issue is fixed in version 1.20.2.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
整数溢出或超界折返
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
klauspost compress < 1.20.2 -

II. Public POCs for CVE-2026-116591

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III. Intelligence Information for CVE-2026-116591

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Other References for CVE-2026-116591 (3)

IV. Related Vulnerabilities

Same product: compress
Same vendor: klauspost
Same weakness: CWE-190