VulnerabilityAwaiting Analysis

CVE-2026-116591

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.

HIGH 8.7EPSS —

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unscored. Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: No score yet
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-190
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.