CVE-2026-53920 (GCVE-0-2026-53920)
Vulnerability from cvelistv5 – Published: 2026-10-23 13:20 – Updated: 2026-10-23 20:58
VLAI
EPSS
VEX
Title
odhcpd DHCPv6 Short IA_NA/IA_PD Body Stack Disclosure
Summary
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.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-23 17:33 UTC
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/openwrt/odhcpd/security/adviso… | x_refsource_CONFIRM |
| https://github.com/openwrt/odhcpd/commit/719fc3ab… | x_refsource_MISC |
| https://github.com/openwrt/odhcpd/commit/f2275efc… | x_refsource_MISC |
Impacted products
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