CVE-2026-71402

MEDIUM
Published Aug 27, 2026 Modified Sep 1, 2026 CWE-125 CWE-130

Description

An out-of-bounds read was found in the DHCPv4 packet capture code of wicked. ni_capture_inspect_udp_header() in src/capture.c reports the IP total length as the payload length instead of the length of the remaining UDP payload. Consequently, the DHCP option walker in the DHCPv4 client (wickedd-dhcp4) reads up to ihl + 8 bytes — at most 68 bytes — past the end of the 1500-byte packet receive buffer. An unauthenticated attacker on the same network who sends a crafted DHCP/UDP packet can make the client parse adjacent heap memory as DHCP options, so that heap contents such as allocator metadata or pointer values can be interpreted into lease fields. The over-read is bounded to 68 bytes; no memory write, no attacker control over the adjacent bytes and no remote exfiltration primitive has been demonstrated. This issue affects wicked up to and including version 0.6.80.

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CVSS v3.1 Score

5.4
MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS — Exploit Prediction

0.0017
Probability of exploitation
0.07%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-125 Out-of-bounds Read
CWE-130 CWE-130

References

Frequently Asked Questions

What is CVE-2026-71402? +
An out-of-bounds read was found in the DHCPv4 packet capture code of wicked. ni_capture_inspect_udp_header() in src/capture.c reports the IP total length as the payload length instead of the length of the remaining UDP payload. Consequently, the DHCP option walker in the DHCPv4 client (wickedd-dhcp4) reads up to ihl + 8 bytes — at most 68 bytes — past the end of the 1500-byte packet receive buffer. An unauthenticated attacker on the same network who sends a crafted DHCP/UDP packet can make the client parse adjacent heap memory as DHCP options, so that heap contents such as allocator metadata or pointer values can be interpreted into lease fields. The over-read is bounded to 68 bytes; no memory write, no attacker control over the adjacent bytes and no remote exfiltration primitive has been demonstrated. This issue affects wicked up to and including version 0.6.80. It has a CVSS v3.1 base score of 5.4 (MEDIUM).
How severe is CVE-2026-71402? +
CVE-2026-71402 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0017, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-71402? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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