# CVE-2026-124747: Busybox: heap buffer overflow in wget ftp resume when the resume offset exceeds the reported file size

Status: published. Published: 2026-11-10. Updated: 2026-11-14.

A flaw was found in BusyBox. When resuming a download over File Transfer Protocol (FTP), the wget utility fails to verify that the resume offset does not exceed the file size reported by the server, resulting in an integer calculation error. A malicious FTP server or an on-path network attacker can exploit this issue by returning crafted file size metadata, triggering a heap-based buffer overflow with attacker-controlled data. Successful exploitation may allow an attacker to execute arbitrary code or crash the application, resulting in a denial of service (DoS).

## Remediation

- workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 6 (busybox): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Hardened Images (busybox): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H; source: CNA: redhat

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H; source: NVD: secalert@redhat.com

- CISA KEV: No listing in collected sources

- EPSS: 0.29% as of 2026-11-13; percentile 22.21%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-787

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/security/cve/CVE-2026-124747 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2569520 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-124747 (secalert@redhat.com)

- https://bugzilla.redhat.com/show_bug.cgi?id=2569520 (secalert@redhat.com)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-124747; retrieved 2026-11-14; source updated 2026-11-14

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-124747; retrieved 2026-11-10; source updated 2026-11-10

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-124747; retrieved 2026-11-14; source updated Not reported

Revision: baafd822bf9fdae7035293c3f09df00e14ca0664f7f5dfc1f5d51a8c52a493fa

Canonical: https://y2.dev/cve/CVE-2026-124747

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