CVE catalog
CVE-2026-56114
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 wri
- Severity
- Medium · CVSS 6
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.27% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | dhcpcd5 | bookworm | 9.4.1-24~deb12u5 | fixed |
| Cpe | dhcpcd | Not reported | Not reported | unknown |
| Alpine | dhcpcd | 3.23 | 10.5.2-r0 | fixed |
| Alpine | dhcpcd | 3.24 | 10.5.2-r0 | fixed |
| Ubuntu | dhcpcd | 24.04 | 1:10.0.2-3ubuntu3 | vulnerable |
| Ubuntu | dhcpcd | 24.04 | 1:10.0.5-1 | vulnerable |
| Ubuntu | dhcpcd | 24.04 | 1:10.0.5-2 | vulnerable |
| Ubuntu | dhcpcd | 24.04 | 1:10.0.5-3 | vulnerable |
| Ubuntu | dhcpcd | 24.04 | 1:10.0.5-4 | vulnerable |
| Ubuntu | dhcpcd | 24.04 | 1:10.0.5-5 | vulnerable |
| Ubuntu | dhcpcd | 24.04 | 1:10.0.6-1 | vulnerable |
| Ubuntu | dhcpcd | 24.04 | 1:10.0.6-1ubuntu1 | vulnerable |
| Ubuntu | dhcpcd | 24.04 | 1:10.0.6-1ubuntu2 | vulnerable |
| Ubuntu | dhcpcd | 24.04 | 1:10.0.6-1ubuntu3 | vulnerable |
| Ubuntu | dhcpcd | 24.04 | 1:10.0.6-1ubuntu3.1 | vulnerable |
| Ubuntu | dhcpcd | 24.04 | 1:10.0.6-1ubuntu3.2 | vulnerable |
| Ubuntu | dhcpcd | 25.10 | 1:10.1.0-8 | vulnerable |
| Ubuntu | dhcpcd | 25.10 | 1:10.1.0-10 | vulnerable |
| Ubuntu | dhcpcd | 25.10 | 1:10.1.0-11 | vulnerable |
| Ubuntu | dhcpcd | 25.10 | 1:10.1.0-12 | vulnerable |
| Ubuntu | dhcpcd | 25.10 | 1:10.2.4-3 | vulnerable |
| Ubuntu | dhcpcd | 25.10 | 1:10.2.4-4 | vulnerable |
| Ubuntu | dhcpcd | 26.04 | 1:10.2.4-4 | vulnerable |
| Ubuntu | dhcpcd | 26.04 | 1:10.3.0-2 | vulnerable |
| Ubuntu | dhcpcd | 26.04 | 1:10.3.0-3 | vulnerable |
| Ubuntu | dhcpcd | 26.04 | 1:10.3.0-7 | vulnerable |
| Cpe | dhcpcd | Not reported | Not reported | unknown |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | dhcpcd5 | source | bookworm | 9.4.1-24~deb12u5 | not yet assigned | Not reported | Not reported |
| Alpine | dhcpcd | apk | 3.23 | 10.5.2-r0 | Not reported | ALPINE-CVE-2026-56114 | Not reported |
| Alpine | dhcpcd | apk | 3.24 | 10.5.2-r0 | Not reported | ALPINE-CVE-2026-56114 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [dhcpcd]Fixed
Details (2)
1:9.4.1-24~deb12u5· all · bookwormFixed · Fixed:
9.4.1-24~deb12u5nvd · dhcpcd5 · debian · bookworm; nvd · dhcpcd5 · debian · 12
1:9.4.1-24~deb12u5· all · bookwormFixed · Fixed:
9.4.1-24~deb12u5nvd · dhcpcd5 · debian · bookworm; nvd · dhcpcd5 · debian · 12
- [dhcpcd5]Fixed
Source package: [dhcpcd]
Details (4)
9.4.1-24~deb12u5· all · bookwormFixed · Fixed:
9.4.1-24~deb12u5nvd · dhcpcd5 · debian · bookworm; nvd · dhcpcd5 · debian · 12
9.4.1-24~deb12u5· all · bookwormFixed · Fixed:
9.4.1-24~deb12u5nvd · dhcpcd5 · debian · bookworm; nvd · dhcpcd5 · debian · 12
1:10.1.0-11~bpo12+3· all · bookworm-backportsFixed · Fixed:
9.4.1-24~deb12u5nvd · dhcpcd5 · debian · bookworm; nvd · dhcpcd5 · debian · 12
1:10.1.0-11~bpo12+3· all · bookworm-backportsFixed · Fixed:
9.4.1-24~deb12u5nvd · dhcpcd5 · debian · bookworm; nvd · dhcpcd5 · debian · 12
- [dhcpcd-base]Fixed
Source package: [dhcpcd]
Details (2)
9.4.1-24~deb12u5· amd64 · bookwormFixed · Fixed:
9.4.1-24~deb12u5nvd · dhcpcd5 · debian · bookworm; nvd · dhcpcd5 · debian · 12
9.4.1-24~deb12u5· arm64 · bookwormFixed · Fixed:
9.4.1-24~deb12u5nvd · dhcpcd5 · debian · bookworm; nvd · dhcpcd5 · debian · 12
[Debian 13 (Trixie)]
- [dhcpcd]Fixed
Details (4)
1:10.1.0-11+deb13u3· all · trixieFixed · Fixed:
1:10.1.0-11+deb13u3nvd · dhcpcd · debian · 13
1:10.1.0-11+deb13u3· all · trixieFixed · Fixed:
1:10.1.0-11+deb13u3nvd · dhcpcd · debian · 13
1:10.5.2-1~bpo13+1· all · trixie-backportsFixed · Fixed:
1:10.1.0-11+deb13u3nvd · dhcpcd · debian · 13
1:10.5.2-1~bpo13+1· all · trixie-backportsFixed · Fixed:
1:10.1.0-11+deb13u3nvd · dhcpcd · debian · 13
- [dhcpcd5]Fixed
Source package: [dhcpcd]
Details (4)
1:10.1.0-11+deb13u3· all · trixieFixed · Fixed:
1:10.1.0-11+deb13u3nvd · dhcpcd · debian · 13
1:10.1.0-11+deb13u3· all · trixieFixed · Fixed:
1:10.1.0-11+deb13u3nvd · dhcpcd · debian · 13
1:10.5.2-1~bpo13+1· all · trixie-backportsFixed · Fixed:
1:10.1.0-11+deb13u3nvd · dhcpcd · debian · 13
1:10.5.2-1~bpo13+1· all · trixie-backportsFixed · Fixed:
1:10.1.0-11+deb13u3nvd · dhcpcd · debian · 13
- [dhcpcd-base]Fixed
Source package: [dhcpcd]
Details (4)
1:10.1.0-11+deb13u3· amd64 · trixieFixed · Fixed:
1:10.1.0-11+deb13u3nvd · dhcpcd · debian · 13
1:10.1.0-11+deb13u3· arm64 · trixieFixed · Fixed:
1:10.1.0-11+deb13u3nvd · dhcpcd · debian · 13
1:10.5.2-1~bpo13+1· amd64 · trixie-backportsFixed · Fixed:
1:10.1.0-11+deb13u3nvd · dhcpcd · debian · 13
1:10.5.2-1~bpo13+1· arm64 · trixie-backportsFixed · Fixed:
1:10.1.0-11+deb13u3nvd · dhcpcd · debian · 13
Observed:
References
- [https://github.com/NetworkConfiguration/dhcpcd/commit/2f00c7bfc408b6582d331932dfa47829c4819029]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-56114]
- [https://osv.dev/vulnerability/ALPINE-CVE-2026-56114]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-56114]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-56114]
- [https://security-tracker.debian.org/tracker/CVE-2026-56114]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-56114.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2046.json]
- [https://www.vulncheck.com/advisories/dhcpcd-stack-out-of-bounds-write-in-dhcp6-makemessage]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]