CVE-2026-58092

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under CISA-ADP (Vulnrichment) CVSS v3.1 (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 89% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: cisa-adp, epss, ghsa
Trending — 5 sources updated this week
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

In FreeBSD 15.0, the kernel structure used to represent user credentials changed: previously the primary group ID was stored in the first element of the array containing the list of supplementary group IDs, whereas now the primary group ID is stored in a dedicated field. This change was largely internal to the kernel and not user-visible.

One function, group_is_primary(), was not properly updated as a part of this transition. This function is used by mac_do to determine the primary group ID of the credential after applying a transition rule, used when the rule target does not explicitly specify a group.

As a result, with certain mac_do rules, it is possible for a credential switch to incorrectly set the primary group ID to the ID stored in the first element of the original credential's supplementary group array.

If the list of supplementary groups is empty, this value will be 0, corresponding to the "wheel" group. For example, a rule such as "uid=1001>uid=1002" can be abused to set the primary group ID to 0 even if the process did not originally belong to group 0.

Certain mac_do rules can be abused to set a process' group ID to 0. Note however, that the rule must apply to the caller in order for the bug to be triggered, e.g., given the ruleset "uid=1001>uid=1002", the user must have user ID 1001 in order to trigger the bug.

Further, logged-in users will in general have a non-empty supplementary group list, in which case the bug can at worst be used to set the credential's first supplementary group ID as its primary group ID. Processes must explicitly remove themselves from all supplementary groups, using the privileged setgroups(2) system call, in order to exploit the bug to set 0 as the primary group ID.

Since membership in group 0 is often used to enable controlled privilege escalation, the bug might be further exploitable to obtain root privileges, depending on the system configuration. For instance, a ruleset such as the following could be exploited by a process running as user 1001 and with an empty supplementary group list: "uid=1001>uid=1002;gid=0>uid=0".

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

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 computed
Severity81% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
11%
KEV
Not listed

Published

August 26, 2026

Last Modified

August 27, 2026

Advisory Details (1)

Auto-updated Aug 26, 2026
No patch confirmed yet.
generic
https://security.freebsd.org/advisories/FreeBSD-SA-26:59.mac_do.asc

Vendor Advisories for CVE-2026-58092(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 21× in last 7d / 21× 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.

  1. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 19:37 UTCGHSA enrichment
  3. 2026-08-29 07:07 UTCEG score recompute
  4. 2026-08-29 07:07 UTCGHSA enrichment
  5. 2026-08-28 21:42 UTCEPSS rescore
  6. 2026-08-28 18:36 UTCGHSA enrichment
  7. 2026-08-28 06:04 UTCGHSA enrichment
  8. 2026-08-27 17:31 UTCGHSA enrichment
  9. 2026-08-27 17:09 UTCEG score recompute▲ 2.70
  10. 2026-08-27 17:09 UTCGHSA enrichment
  11. 2026-08-27 16:43 UTCMITRE cvelistV5CVSS v3 → 8.1 · severity → HIGH
  12. 2026-08-27 14:25 UTCEPSS rescore
  13. 2026-08-27 04:26 UTCGHSA enrichment
  14. 2026-08-27 04:03 UTCEG score recompute
  15. 2026-08-27 04:02 UTCGHSA enrichment
  16. 2026-08-26 15:55 UTCEG score recompute▲ 5.40
  17. 2026-08-26 15:54 UTCMITRE cvelistV5CVSS v3 → 5.4 · severity → MEDIUM
  18. 2026-08-26 15:43 UTCNVD update
  19. 2026-08-26 14:46 UTCEPSS rescore
  20. 2026-08-26 04:55 UTCEG score recompute
  21. 2026-08-26 04:54 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-58092?
CVE-2026-58092 is a high vulnerability published on August 26, 2026. In FreeBSD 15.0, the kernel structure used to represent user credentials changed: previously the primary group ID was stored in the first element of the array containing the list of supplementary group IDs, whereas now the primary group ID is stored in a dedicated field. This change was largely…
When was CVE-2026-58092 disclosed?
CVE-2026-58092 was first published in the National Vulnerability Database on August 26, 2026, with the most recent update on August 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-58092 actively exploited?
CVE-2026-58092 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 88.6% of all scored CVEs.
What is the CVSS score of CVE-2026-58092?
CVE-2026-58092 has a CVSS v3.1 base score of 8.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-58092?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-58092, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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