Busybox: busybox: passwd/group parser writes heap pointers out of bounds due to stale tokenize() endpoint
Summary
| CVE | CVE-2026-88839 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-23 18:17:10 UTC |
| Updated | 2026-09-25 23:16:54 UTC |
| Description | BusyBox passwd/group tokenize() references a stale endpoint pointer after trimming, causing an out-of-bounds write of heap pointers. |
Risk And Classification
Primary CVSS: v3.1 6.7 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.001230000 probability, percentile 0.018080000 (date 2026-09-27)
Problem Types: CWE-787 | CWE-787 Out-of-bounds Write
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 6.7 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 6.7 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
HighUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Hardened Images | unaffected 1.37.0-9.1.hum1 * rpm | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/security/cve/CVE-2026-88839 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:72111 | [email protected] | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank Shubham Raj (Causal Security) for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-09-09T00:00:00.000Z | Reported to Red Hat. |
| CNA | 2026-09-23T16:35:00.000Z | Made public. |
Workarounds
CNA: Ensure /etc/group and /etc/passwd are writable only by root and protected by mandatory access controls. Monitor these files for unauthorized modifications. Upstream should fix tokenize() to recompute tokenize_end after trimming.
There are currently no legacy QID mappings associated with this CVE.