CVE-2026-88833
Busybox: busybox: udhcpc integer underflow in dhcp packet length calculation causes denial of service
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.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
6.5
Busybox: busybox: udhcpc integer underflow in dhcp packet length calculation causes denial of service
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.
- Record
CVE-2026-88833- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-191
- Updated
- 2026-11-02
EUVDEUVD-2026-98897
6.5
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.
- Record
EUVD-2026-98897- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-hg7w-cw6w-99w3
6.5
A flaw was found in BusyBox's udhcpc DHCP client. When processing raw DHCP packets, the client...
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.
- Record
GHSA-hg7w-cw6w-99w3- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-191
- Updated
- 2026-11-02
NVD
6.5
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.
- Record
CVE-2026-88833- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-191
- Updated
- 2026-11-02
OSVBELL-CVE-2026-88833
6.5
- Record
BELL-CVE-2026-88833- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-88833
6.5
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.
- Record
DEBIAN-CVE-2026-88833- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-88833
6.5
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.
- Record
UBUNTU-CVE-2026-88833- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVAZL-108321 No score
CVE-2026-88833 affecting package busybox 1.36.1-28
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.
- Record
AZL-108321- Updated
- 2026-11-05
OSVopenSUSE-SU-2026:12376-1 No score
busybox-1.38.0-4.1 on GA media
These are all security issues fixed in the busybox-1.38.0-4.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:12376-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
busyboxAzure Linux:3 |
through 1.36.1-28 | None known |
busyboxAlpaquita:23 |
1.35.0-r29 up to 1.35.0-r42 | 1.35.0-r42 |
busyboxAlpaquita:25 |
1.37.0-r20 up to 1.37.0-r29 | 1.37.0-r29 |
busyboxAlpaquita:stream |
1.36.1-r1 up to 1.38.0-r6 | 1.38.0-r6 |
busyboxBellSoft Hardened Containers:23 |
1.35.0-r29 up to 1.35.0-r42 | 1.35.0-r42 |
busyboxBellSoft Hardened Containers:25 |
1.37.0-r20 up to 1.37.0-r29 | 1.37.0-r29 |
busyboxBellSoft Hardened Containers:stream |
1.36.1-r1 up to 1.38.0-r6 | 1.38.0-r6 |
busyboxDebian:12 |
All versions, plus listed versions 1:1.35.0-41:1.35.0-4+deb12u11:1.36.0-1~exp11:1.36.1-11:1.36.1-2 Show 23 moreShow less1:1.36.1-31:1.36.1-3.11:1.36.1-41:1.36.1-51:1.36.1-61:1.36.1-6~exp.11:1.36.1-71:1.36.1-81:1.36.1-91:1.37.0-11:1.37.0-101:1.37.0-10.11:1.37.0-21:1.37.0-31:1.37.0-41:1.37.0-51:1.37.0-61:1.37.0-71:1.37.0-81:1.37.0-91:1.38.0-11:1.38.0-21:1.38.0-3 |
None known |
busyboxDebian:13 |
All versions, plus listed versions 1:1.37.0-101:1.37.0-10.11:1.37.0-61:1.37.0-71:1.37.0-8 Show 4 moreShow less1:1.37.0-91:1.38.0-11:1.38.0-21:1.38.0-3 |
None known |
busyboxDebian:14 |
All versions, plus listed versions 1:1.37.0-101:1.37.0-10.11:1.37.0-61:1.37.0-71:1.37.0-8 Show 4 moreShow less1:1.37.0-91:1.38.0-11:1.38.0-21:1.38.0-3 |
None known |
Show 9 moreShow less
| Package | Affected | Fixed |
|---|---|---|
busyboxUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 1:1.20.0-8.1ubuntu11:1.20.0-9ubuntu11:1.20.0-9ubuntu21:1.21.0-1ubuntu11:1.21.0-1ubuntu1.41:1.21.0-1ubuntu1.4+esm1 |
None known |
busyboxUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 1:1.22.0-15ubuntu11:1.22.0-15ubuntu1.41:1.22.0-15ubuntu1.4+esm11:1.22.0-15ubuntu1.4+esm2 |
None known |
busyboxUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 1:1.22.0-19ubuntu21:1.27.2-1ubuntu31:1.27.2-1ubuntu41:1.27.2-2ubuntu21:1.27.2-2ubuntu3 Show 5 moreShow less1:1.27.2-2ubuntu3.11:1.27.2-2ubuntu3.21:1.27.2-2ubuntu3.31:1.27.2-2ubuntu3.41:1.27.2-2ubuntu3.4+esm1 |
None known |
busyboxUbuntu:20.04:LTS |
All versions, plus listed versions 1:1.30.1-4ubuntu41:1.30.1-4ubuntu51:1.30.1-4ubuntu61:1.30.1-4ubuntu6.11:1.30.1-4ubuntu6.21:1.30.1-4ubuntu6.31:1.30.1-4ubuntu6.41:1.30.1-4ubuntu6.5 |
None known |
busyboxUbuntu:22.04:LTS |
All versions, plus listed versions 1:1.30.1-6ubuntu31:1.30.1-7ubuntu11:1.30.1-7ubuntu21:1.30.1-7ubuntu31:1.30.1-7ubuntu3.1 |
None known |
busyboxUbuntu:24.04:LTS |
All versions, plus listed versions 1:1.36.1-3ubuntu11:1.36.1-6ubuntu11:1.36.1-6ubuntu31:1.36.1-6ubuntu3.1 |
None known |
busyboxUbuntu:26.10 |
All versions, plus listed versions 1:1.37.0-7ubuntu11:1.37.0-10.1ubuntu21:1.37.0-10.1ubuntu31:1.38.0-3ubuntu11:1.38.0-3ubuntu31:1.38.0-3ubuntu4 |
None known |
busyboxUbuntu:26.04:LTS |
All versions, plus listed versions 1:1.37.0-4ubuntu11:1.37.0-7ubuntu1 |
None known |
busyboxopenSUSE:Tumbleweed From an advisory covering 8 CVEs |
before 1.38.0-4.1 | 1.38.0-4.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected | ||
| facts | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-88833 is a medium vulnerability (CVSS 6.5) in Red Hat Hardened Images, published October 13, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.19%, the 8th percentile. Fixed in busybox 1.35.0-r42.
References
access.redhat.com/security/cve/CVE-2026-88833
bugzilla.redhat.com/show_bug.cgi?id=2531347
nvd.nist.gov/vuln/detail/CVE-2026-88833
github.com/advisories/GHSA-hg7w-cw6w-99w3
docs.bell-sw.com/security/cves/CVE-2026-88833
security-tracker.debian.org/tracker/CVE-2026-88833
Show 10 moreShow less
ubuntu.com/security/CVE-2026-88833
cve.org/CVERecord?id=CVE-2026-88833
suse.com/security/cve/CVE-2024-58251
suse.com/security/cve/CVE-2026-108119
suse.com/security/cve/CVE-2026-88829
suse.com/security/cve/CVE-2026-88833
suse.com/security/cve/CVE-2026-88834
suse.com/security/cve/CVE-2026-88842
suse.com/security/cve/CVE-2026-90954
suse.com/security/cve/CVE-2026-92205