CVE-2026-93009
Dnsmasq: dnsmasq: heap out-of-bounds read in dhcpv6 option 39 fqdn decoder
Description
A flaw was found in dnsmasq. The DHCPv6 client hostname parser can read one byte past the end of a crafted FQDN option because it checks the next label length before confirming the pointer is still inside the option. An attacker on the local network can trigger this with a single DHCPv6 packet. The extra byte is not returned to the client or logged, and no crash has been demonstrated.
INFO
Published Date :
Oct. 29, 2026, 2:18 p.m.
Last Modified :
Oct. 29, 2026, 2:18 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-93009
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 53f830b8-0a3f-465b-8143-3b8a9948e749 | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update dnsmasq to the latest version.
- Apply vendor patches for dnsmasq.
- Restart the dnsmasq service.
- Monitor network for suspicious DHCPv6 traffic.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-93009.
| URL | Resource |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-93009 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2536083 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-93009 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-2026-93009
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-93009 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-93009 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Oct. 29, 2026
Action Type Old Value New Value Added Description A flaw was found in dnsmasq. The DHCPv6 client hostname parser can read one byte past the end of a crafted FQDN option because it checks the next label length before confirming the pointer is still inside the option. An attacker on the local network can trigger this with a single DHCPv6 packet. The extra byte is not returned to the client or logged, and no crash has been demonstrated. Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Added CWE CWE-125 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93009.json">CVE-2026-93009</a> Added Reference https://access.redhat.com/security/cve/CVE-2026-93009 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2536083