VulnerabilityPublished 29 Oct 2026

CVE-2026-93009: Red Hat Ceph Storage 9 · Out-of-bounds Read

Affects Red Hat Ceph Storage 9Source CVE Database V5

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Not known to be exploited · CVSS 4.3 Medium.

Data as of 29 Oct 2026, 14:52 UTC

CVSS 3.1 base score

4.3Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (redhat)	CVSS 3.1	4.3

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Attack Vector: Adjacent
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Adjacent: The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 29 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Red Hat Ceph Storage 9rhceph/alloy-rhel10	Affected–	Fixed in–
Red Hat Enterprise Linux 10dnsmasq	Affected–	Fixed in–
Red Hat Enterprise Linux 6dnsmasq	Affected–	Fixed in–
Red Hat Enterprise Linux 7dnsmasq	Affected–	Fixed in–
Red Hat Enterprise Linux 8dnsmasq	Affected–	Fixed in–
Red Hat Enterprise Linux 9dnsmasq	Affected–	Fixed in–

AI-suggested

Red Hat rates this vulnerability as low severity and provides the following mitigations: (1) Do not configure any IPv6 DHCP range if DHCPv6 is not required; (2) Compile dnsmasq without DHCPv6 support using COPTS=-DNO_DHCP6 if IPv6 DHCP is unnecessary; (3) Restrict dnsmasq to trusted interfaces using the --interface=<iface> option.

Description

CVE-2026-93009 is an out-of-bounds read vulnerability in the dnsmasq DHCPv6 client hostname parser used in Red Hat Ceph Storage 9. The flaw allows reading one byte past the end of a crafted Fully Qualified Domain Name (FQDN) option due to insufficient boundary checks. This can be triggered by an attacker on the local network sending a single DHCPv6 packet. No crash or data leak has been demonstrated, and the vulnerability is rated as low impact.

Impact

The vulnerability allows an adjacent network attacker to cause dnsmasq to read one byte beyond the intended buffer boundary when parsing DHCPv6 client hostname options. However, the out-of-bounds read does not result in data leakage, crash, or denial of service. The impact is limited to a low confidentiality impact with no integrity or availability effects.

Summary

This vulnerability exists in dnsmasq's DHCPv6 client hostname parser, which improperly checks the next label length before confirming the pointer remains inside the option, resulting in a one-byte out-of-bounds read. The flaw can be triggered by a local network attacker sending a crafted DHCPv6 packet. The extra byte read is not returned to the client or logged, and no crash has been demonstrated. Red Hat products shipping dnsmasq with DHCPv6 compiled in may be affected when a DHCPv6 range is configured. RHEL 6 ships dnsmasq 2.48, which predates the vulnerability, while later RHEL streams ship 2.76 or newer and include the vulnerable parser. The vulnerability is rated low severity due to the limited impact of a single-byte read without demonstrated exploitation.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 29 Oct 2026, 13:51 UTC

Technical details

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