Answer in brief
CVE-2026-61801 records a Medium severity (CVSS 5.5) vulnerability in github.com/moby/sys/user has a possible DoS via unbounded parsing of user and group database files. The current sources do not mark it as known exploited. The current feed maps moby/sys (generic), github.com/moby/sys/user (go), github.com/moby/sys/user (go). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps moby/sys (generic), github.com/moby/sys/user (go), github.com/moby/sys/user (go). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| moby/sysgeneric | <0.4.1 | 0.4.1 |
| github.com/moby/sys/usergo | <=0.4.0 | 0.4.1 |
| github.com/moby/sys/usergo | >=0 <0.4.1 | 0.4.1 |
Published upstream
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 8, 2026
The `github.com/moby/sys/user` package provides Go utilities for parsing and looking up entries in Unix-style user and group database files. Versions before 0.4.1 do not sufficiently limit entries when parsing `/etc/passwd`- or `/etc/group`-style files, allowing an attacker who can supply a specially crafted file to cause excessive memory consumption and potentially terminate the affected process due to an out-of-memory condition. This issue is patched in version 0.4.1. As a workaround, avoid parsing attacker-controlled user or group database files, or validate and limit untrusted input before parsing it.
Quoted source text, attributed separately from HOL analysis.