Busybox: busybox: tls montgomery reduction allocates bytes instead of digits, causing a pre-auth heap buffer overflow
Summary
| CVE | CVE-2026-88830 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-23 17:17:18 UTC |
| Updated | 2026-09-23 20:17:20 UTC |
| Description | A unit confusion in BusyBox TLS Montgomery reduction buffer allocation causes a pre-authentication heap buffer overflow when processing a crafted ClientKeyExchange message. |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.003510000 probability, percentile 0.259600000 (date 2026-09-24)
Problem Types: CWE-131 | CWE-131 Incorrect Calculation of Buffer Size
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Hardened Images | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/security/cve/CVE-2026-88830 | [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 |
No vendor comments have been submitted for this CVE.
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: Do not use the BusyBox ssl_server applet in production environments. Use a well-maintained TLS implementation such as OpenSSL or GnuTLS instead. Ensure system-level exploit mitigations (ASLR, PIE, RELRO, stack protectors) are enabled.
There are currently no legacy QID mappings associated with this CVE.