odhcpd: Stack buffer overread via DUID length endianness mismatch in memcmp()
CVSS score
6.5
EPSS probability
—
Risk score
0.7
Published
4 h ago
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Impact on My Inventory
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Vulnerability description
DayBreach AI Explanation
Verified against sourcesSources read
1
Source agreement
Tam uyum
Evidence confidence
%55
Short explanation
An issue in odhcpd used by OpenWrt allows a stack buffer overread due to an endianness mismatch of the DUID length in memcmp() on little-endian hosts. A single unauthenticated DHCPv6 packet can trigger a 2560-byte overread from a 128-byte buffer.
The vulnerability allows unauthenticated remote attackers to target network services, potentially causing information disclosure or denial of service.
What should be done?
- Follow vendor advisories for updates
- Monitor package and source code changes
- Review security advisories
Chain of evidence and sources
odhcpd 25.12 ve önceki sürümlerde memcmp() içinde DUID uzunluğu bayt sırası uyuşmazlığı nedeniyle yığın arabellek sınır ötesi okuma zafiyeti bulunmaktadır.
Kimlik doğrulaması gerektirmeyen tek bir DHCPv6 paketi, 128 baytlık bir arabellekten 2560 baytlık okuma tetikleyebilir.
Yayınlanma zamanında genel kullanıma açık herhangi bir yama bulunmamaktadır ve yama durumu belirsizdir.
Show the technical text from the sources
odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. In versions 25.12 and prior, odhcpd's DHCPv6 self-loop detection at dhcpv6.c:720 uses a network-byte-order DUID length value directly as the memcmp() size parameter. On little-endian hosts, this causes memcmp() to read far beyond the stack buffer — a single unauthenticated DHCPv6 packet triggers a 2560-byte overread from a 128-byte buffer. At time of publication, there are no publicly available patches.
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
CWE: CWE-126
This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.
IMPACT: Affected Products and Software
Affected Products
The following products are affected by CVE-2026-55606 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.
| ID | VENDOR | PRODUCT | ACTION |
|---|---|---|---|
| 1 | openwrt | odhcpd | View |
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| 6.5 | CVSS V3_1 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L | CVE CNA |
| 6.5 | CVSS V31 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L | NVD |
Patch and Remediation Guide
Solution & Remediation Advisory
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Public exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-55606 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-55606 weaknesses.
Attack Vector and Accessibility
Official Sources and Advisories
Similar Vulnerabilities
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