High 8.7Published Oct 23, 2026

CVE-2026-53920odhcpd DHCPv6 Short IA_NA/IA_PD Body Stack Disclosure

Updated under an hour ago (Oct 28, 2026, 12:30 AM ET)

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It affects openwrt odhcpd. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.40%, higher than 33% of scored CVEs.

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Every CVE for openwrt odhcpd

Exploited in the last 30 days

odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. From version 17.01.0 to before version 25.12.3, odhcpd's DHCPv6 IA parser accepts an IA_NA or IA_PD option whose body is shorter than struct dhcpv6_ia_hdr, casts the option header to that full structure, and reads ia->iaid before proving that the IA body contains the IAID field. If an unauthenticated network-adjacent client places a zero-length or otherwise short IA option at the end of odhcpd's 8192-byte receive stack buffer, the IAID read crosses from data_buf into adjacent stack memory. The disclosed bytes are then reflected in the DHCPv6 reply IAID; prior ARM validation showed data_buf[8192:8196] disclosing the saved stack canary, and wider stack scans can leak ASLR-useful stack/process contents. This issue has been patched in version 25.12.3.

CVSS: 8.7 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness (CWE): CWE-125, CWE-126, CWE-200, CWE-201
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.40% (percentile 33)
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Oct 23, 2026
First seen by InfoSec Signals: Oct 23, 2026

Affected products

Affected products

openwrt odhcpd openwrt:odhcpd (from the name)	from 17.01.0, < 25.12.3	CNA record

References

References

https://github.com/openwrt/odhcpd/security/advisories/GHSA-p769-5v73-pc4f	x-refsource-confirm
https://github.com/openwrt/odhcpd/commit/719fc3abc0d7e7059871f9f572fb05ada86b8ff2	x-refsource-misc
https://github.com/openwrt/odhcpd/commit/f2275efc72a87a95f971f159babcbadc5d241d42	x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.