CVE-2026-56115: Out-of-bounds Write in NetworkConfiguration dhcpcd
dhcpcd through 10.3.2, fixed in commit 2f00c7b, contains a one-byte stack out-of-bounds write vulnerability in dhcp6_makemessage() in src/dhcp6.c that allows unauthenticated same-link attackers to write beyond a fixed local buffer by serializing an oversized RFC6603 OPTION_PD_EXCLUDE option body. Attackers can send a crafted DHCPv6 ADVERTISE message containing an IA_PD IAPREFIX /0 with a valid OPTION_PD_EXCLUDE using an exclude prefix length of /121 through /128 to trigger the out-of-bounds write and potentially corrupt adjacent stack memory.
CVE-2026-56115: Out-of-bounds Write in NetworkConfiguration dhcpcd
Description
dhcpcd through 10.3.2, fixed in commit 2f00c7b, contains a one-byte stack out-of-bounds write vulnerability in dhcp6_makemessage() in src/dhcp6.c that allows unauthenticated same-link attackers to write beyond a fixed local buffer by serializing an oversized RFC6603 OPTION_PD_EXCLUDE option body. Attackers can send a crafted DHCPv6 ADVERTISE message containing an IA_PD IAPREFIX /0 with a valid OPTION_PD_EXCLUDE using an exclude prefix length of /121 through /128 to trigger the out-of-bounds write and potentially corrupt adjacent stack memory.
CVSS v4.0
Score 6.0medium
Affected software
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Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-06-18T19:15:10.650Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a3ab6dbeed863c81e4f9f63
Added to database: 06/23/2026, 16:39:55 UTC
Last updated: 06/23/2026, 16:39:55 UTC
Views: 1
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