High 8.7Published Oct 26, 2026

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

Updated under an hour ago (Oct 28, 2026, 2:00 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for klauspost compress

Exploited in the last 30 days

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.

CVSS: 8.7 HIGH (v4.0, CNA)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
Weakness (CWE): CWE-190
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Awaiting Analysis
Record last updated: Oct 27, 2026
First seen by InfoSec Signals: Oct 26, 2026

Affected products

Affected products

klauspost compress klauspost:compress (from the name)	before 1.20.2	CNA record

References

References

https://github.com/klauspost/compress/security/advisories/GHSA-fpmh-frq8-7rj8	x-refsource-confirm
https://github.com/klauspost/compress/commit/7f5d8528720c895a6106f201719f87eb030a565d	x-refsource-misc
https://github.com/klauspost/compress/releases/tag/v1.20.2	x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.