Vulnerability · Published Oct 26, 2026 · Assigned by GitHub_M
CVE-2026-116591compress zstd: Panic on two-block frames
High 8.7
In plain English
A high-severity integer overflow in compress from klauspost. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.24 | docker | 29.9.3-r0 | ALPINE-CVE-2026-116591 |
| Debian:12 | golang-github-klauspost-compress | no fix listed | DEBIAN-CVE-2026-116591 |
| Debian:13 | golang-github-klauspost-compress | no fix listed | DEBIAN-CVE-2026-116591 |
| Debian:14 | golang-github-klauspost-compress | 1.20.3+ds1-1 | DEBIAN-CVE-2026-116591 |
| Go | github.com/klauspost/compress | 1.20.2 | GO-2026-6865 |
| Go | github.com/klauspost/compress/zstd | 1.20.2 | GHSA-fpmh-frq8-7rj8 |
| Ubuntu:22.04:LTS | golang-github-klauspost-compress | no fix listed | UBUNTU-CVE-2026-116591 |
| Ubuntu:24.04:LTS | golang-github-klauspost-compress | no fix listed | UBUNTU-CVE-2026-116591 |
| Ubuntu:26.04:LTS | golang-github-klauspost-compress | no fix listed | UBUNTU-CVE-2026-116591 |
| Ubuntu:26.10 | golang-github-klauspost-compress | no fix listed | UBUNTU-CVE-2026-116591 |
Affected products (as reported)
Weakness: CWE-190 · Vector: 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