One-byte out-of-bounds read via truncated ClientHello
Published Sep 23, 2026 · Updated Sep 23, 2026
Out-of-bounds read in BusyBox TLS ssl_server allows remote attackers to trigger a one-byte over-read with a truncated ClientHello. get_client_hello reads one byte past the input buffer while parsing the incomplete handshake message. The ssl_server component must accept attacker-controlled TLS connections; the public evidence does not characterize a crash, disclosure, or code-execution consequence.
Summary
What happened
Out-of-bounds read in BusyBox TLS ssl_server allows remote attackers to trigger a one-byte over-read with a truncated ClientHello. get_client_hello reads one byte past the input buffer while parsing the incomplete handshake message. The ssl_server component must accept attacker-controlled TLS connections; the public evidence does not characterize a crash, disclosure, or code-execution consequence.
The record
- CVE
- CVE-2026-88840
- Published
- Sep 23, 2026
- Updated
- Sep 23, 2026
- Vendor
- Commonhaus Foundation
- Product
- Red Hat Hardened Images
- Classifications
- Unavailable
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 23, 2026CVE publishedPublication date reported by the CVE source.
- Sep 23, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Get started to see how Hinoki identifies affected software and validates exploitability in your environment.
Get started