TI-2026-71922 Aliases CVE-2026-88833 GHSA-hg7w-cw6w-99w3

BusyBox udhcpc DHCP client integer underflow allows denial of service

LOW 28CWE-191Published 2026-10-13 · Updated 2026-10-16

Key facts

Attack vector: Adjacent network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-191 and the CVSS impact.

Summary

The BusyBox udhcpc DHCP client mishandles raw DHCP packets. It replaces the validated packet length with a value taken from the attacker-controlled IP header without rechecking the minimum size, which causes an integer underflow (CWE-191) and an oversized memory copy. An attacker on the same network segment can send a specially crafted packet to crash the client, causing denial of service and loss of network connectivity. The sources report no exploitation.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

A flaw was found in BusyBox's udhcpc DHCP client. When processing raw DHCP packets, the client replaces the validated packet length with an attacker-controlled value from the IP header without re-validating the minimum size. This leads to an integer underflow when subtracting header sizes, causing a subsequent memory copy with a massively oversized length. An attacker on the same network segment can send a specially crafted packet to crash the DHCP client, resulting in denial of service and loss of network connectivity.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00189 8th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Red Hat	Red Hat Hardened Images	—	—	No fix listed	CNA

Red Hat Hardened Images VendorRed Hat Affected — Fixed in — No fix listed CNA

CPE names CNA · 1

CPE	Versions	Role	Vendor
cpe:/a:redhat:hummingbird:1	1	—	Red Hat

cpe:/a:redhat:hummingbird:1 Versions 1 — ·Red Hat

Remediation

The sources list no fixed version for Red Hat Hardened Images. Red Hat has no fix plan available for Red Hat Hardened Images.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Hardened Images	Affected	No fix yet

Timeline

2026-10-13 Threatist record created from CVE-2026-88833
2026-10-13 Alias added: GHSA-hg7w-cw6w-99w3
2026-10-14 Priority changed: MEDIUM → LOW
2026-10-15 Affected versions changed · Red Hat
2026-10-15 CVSS score added · Red Hat
2026-10-18 CISA SSVC decision points changed

References

Other 2

TI-2019-15875 Protection mechanism failure in Jenkins Pipeline: Groovy Plugin KEVCVSS 3.1CRITICAL 9.9
TI-2019-15874 Protection mechanism failure in Jenkins Script Security Plugin KEVCVSS 3.1CRITICAL 9.9
TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8

See all 7413 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences