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CVE-2026-88840 Red Hat CVE debrief

CVE-2026-88840 is a MEDIUM-severity vulnerability in BusyBox TLS get_client_hello() that reads past the end of the input buffer when parsing a truncated ClientHello message. The CVE record was published on 2026-09-23T18:17:10.790Z and has not been modified since then. The NVD entry is currently Awaiting Analysis. Defenders responsible for BusyBox deployments, network security teams, and vulnerability management teams should assess exposure and potential impacts. This vulnerability could lead to potential information disclosure due to buffer read. Verification of BusyBox deployments for exposure and assessment of network security impacts are crucial.

Vendor
Red Hat
Product
Red Hat Hardened Images
CVSS
MEDIUM 5.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-23
Original CVE updated
2026-09-26
Advisory published
2026-09-23
Advisory updated
2026-09-26

Who should care

Defenders responsible for BusyBox deployments, network security teams, and vulnerability management teams should assess exposure and potential impacts.

Why it matters

CVE-2026-88840 is a MEDIUM-severity vulnerability in BusyBox TLS get_client_hello() that reads past the end of the input buffer when parsing a truncated ClientHello message. Defenders should prioritize verifying exposure in BusyBox deployments and assessing potential impacts on network security.

  • Potential information disclosure due to buffer read
  • Verification of BusyBox deployments for exposure
  • Assessment of network security impacts
  • Monitoring for patches or updates from the vendor

Technical summary

The BusyBox TLS get_client_hello() function reads past the end of the input buffer when parsing a truncated ClientHello message, potentially leading to information disclosure. This could allow attackers to access sensitive information. The vulnerability affects BusyBox deployments and requires verification of exposure and assessment of network security impacts. The technical details indicate a need for defenders to prioritize verifying exposure in BusyBox deployments and assessing potential impacts on network security.

Defensive priority

Defenders should prioritize verifying exposure in BusyBox deployments and assessing potential impacts on network security.

Recommended defensive actions

  • Verify BusyBox deployments for potential exposure
  • Assess network security impacts
  • Monitor for patches or updates from the vendor

Evidence notes

The CVE record and NVD entry provide initial details on the vulnerability. Red Hat has provided references for further information. The vulnerability has been described as a MEDIUM-severity issue in BusyBox TLS get_client_hello(). The NVD entry and CVE record provide source-provided CVE metadata and official NIST NVD detail page and source-specific vulnerability assessment. However, detailed analysis and verification of exposure in BusyBox deployments are required to understand the of

Sources and references

Verified primary and authoritative sources

  • CVE-2026-88840 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-88840

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-88840 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-88840

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.