Microsoft · compress zstd: Panic on two-block frames
Affects MicrosoftSource GCVE Database
Not known to be exploited · CVSS 8.7 High : upgrade to 1.20.2 soon.
Data as of 31 Oct 2026, 08:23 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 4.0 | 8.7 |
|---|
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.20.2
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 26 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade compress to 1.20.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| klauspostcompress | Affected
| Fixed in
|
Description
CVE-2026-116591 is a vulnerability in the compress zstd component of Microsoft software version 3.0 that causes a panic when processing two-block frames. The issue relates to an integer overflow or similar error classified under CWE-190. No CVSS score or detailed impact information is provided.