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.
CVE-2026-61801
MEDIUMPre-NVD 5.55.5—Trending — Patch released this week
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 5.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1% (1st percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 5.5Exploit: None knownExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 5.5
- EG Score
- 5.5MEDIUMmedium confidence
- EG Risk
- 25EG Risk 25/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity55% × 45%Exploitation0% × 40%Automatability0% × 15%CISA SSVC: Track at every mission impact level.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 0.1%
- EPSS %ILE
- 1st
- KEV
- Not listed
CISA SSVCTrack at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
October 8, 2026
Last Modified
October 8, 2026
Advisory Details (3)
Auto-updated Oct 8, 2026Patch available. Sources: github_commit, github_pr, github.
githubMentions a patch (unverified)
Possible DoS via unbounded parsing of user and group database files · Advisory · moby/sys · GitHub
https://github.com/moby/sys/security/advisories/GHSA-mjcv-p78q-w5fwgithub_pr Patch Available
user: prevent falling back to looking up numeric usernames
Patch available: moby/sys user/v0.4.1 (PR #221 merged 2026-06-23)
https://github.com/moby/sys/pull/221github_commit Patch Available
commit 85a71bbe1faa (moby/sys)
Patch available: moby/sys user/v0.4.1 (contains commit 85a71bbe1faa)
https://github.com/moby/sys/commit/85a71bbe1faa36c552a960e6a5f3d0cfb632fbbeVendor Advisories for CVE-2026-61801(4)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- GHSA-mjcv-p78q-w5fwGitHub Security AdvisoriesMedium
github.com/moby/sys/user has a possible DoS via unbounded parsing of user and group database files
- RHSA-2026:76677Red Hat Product SecurityMedium
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
- RHSA-2026:76448Red Hat Product SecurityMedium
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
- RHSA-2026:76430Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
Patch Availability(3)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| redhat | grafana12-4-main-12.4.12-0.4.hum1 | 2026-10-06 | redhat |
| redhat | grafana13-1-main-13.1.7-0.1.hum1 | 2026-10-05 | redhat |
| redhat | grafana13-2-main-13.2.3-0.1.hum1 | 2026-10-05 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(1 across 1 ecosystem)
Go(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| github.com/moby/sys/user | — |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 10× in last 7d / 10× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-10-10 23:55 UTCEG score recompute
- 2026-10-10 23:55 UTCVendor advisory
- 2026-10-10 20:00 UTCEPSS rescore
- 2026-10-09 22:46 UTCEG score recompute
- 2026-10-09 22:46 UTCVendor advisory
- 2026-10-09 20:07 UTCEPSS rescore
- 2026-10-08 18:36 UTCEG score recompute
- 2026-10-08 17:31 UTCEG score recompute
- 2026-10-08 17:26 UTCEG score recompute
- 2026-10-08 16:26 UTCEG score recompute
Related CVEs(same vendor + same CWE)
Same vendor
4 shownredhat:RHSA-2026:76430
Frequently asked(5)
What is CVE-2026-61801?
CVE-2026-61801 is a medium vulnerability published on October 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…
When was CVE-2026-61801 disclosed?
CVE-2026-61801 was first published on October 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-61801 actively exploited?
CVE-2026-61801 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-61801?
CVE-2026-61801 has a CVSS base score of 5.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-61801?
A fix for CVE-2026-61801 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-61801 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-61801
Is Your Infrastructure Affected by CVE-2026-61801?
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