CVE-2026-23136
Public on
Last Modified:
Description
A flaw was found in the Linux kernel's libceph OSD client. When a connection fault occurs during a sparse read, the sparse-read state is not properly reset. This allows a misbehaving or compromised Ceph OSD server, or a network adversary, to disrupt traffic. As a result, the client can misinterpret new data as a continuation of previous data, leading to a persistent failure mode, repeated errors, and continuous retry loops, effectively causing a Denial of Service (DoS) for Ceph clients performing sparse reads.
Statement
A reliability and availability issue exists in the libceph OSD client sparse read handling. The client tracks progress of a sparse read reply using a separate state machine. When a connection fault happens mid payload or when the sparse read state machine returns an error, the connection is abandoned and later reestablished and pending operations are retried. However the sparse read state was not reset on the fault path. As a result the client can misinterpret the beginning of a new reply as a continuation of the previous reply. This can drive the sparse read machinery into a persistent failure mode that may never recover, producing repeated error messages and repeated socket read failures, effectively preventing successful reads and causing continuous retry loops. From a threat perspective the trigger can be a misbehaving or compromised Ceph OSD server, or a network adversary able to disrupt or truncate traffic, causing fault and retry sequences. The primary impact is denial of service for Ceph clients performing sparse reads.
Additional Information
- This content is not included.Bugzilla 2439852: kernel: Linux kernel: Denial of Service in libceph OSD client due to unreset sparse-read state
- Content from cwe.mitre.org is not included.CWE-440: Expected Behavior Violation
- FAQ: Frequently asked questions about CVE-2026-23136
- Offline Security Data data is available for integration with other systems. See Offline Security Data API to get started.
External References
Content from www.cve.org is not included.https://www.cve.org/CVERecord?id=CVE-2026-23136
Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2026-23136
Affected Packages and Issued Red Hat Security Errata
| Products / Services | Components | State | Errata |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Affected | |
| Red Hat Enterprise Linux 6 | kernel | Not affected | |
| Red Hat Enterprise Linux 7 | kernel | Not affected | |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | |
| Red Hat Enterprise Linux 8 | kernel | Not affected | |
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | |
| Red Hat Enterprise Linux 9 | kernel-rt | Affected | |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2026:13565 |
| Red Hat Enterprise Linux 9 | kernel | Fixed | This content is not included.RHSA-2026:19568 |
Common Vulnerability Scoring System (CVSS) Score Details
Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authorities (CNA) source for its products and services (see Red Hat classifications ).
| CVSS v3 Score Breakdown | Red Hat | NVD |
|---|---|---|
| CVSS v3 Base Score | 7.6 | 5.5 |
| Attack Vector | Adjacent Network | Local |
| Attack Complexity | Low | Low |
| Privileges Required | None | Low |
| User Interaction | None | None |
| Scope | Unchanged | Unchanged |
| Confidentiality Impact | Low | None |
| Integrity Impact | Low | None |
| Availability Impact | High | High |
CVSS v3 Vector
Red Hat CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
NVD CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
For more information, see https://access.redhat.com/solutions/762393.
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
- "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
- "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.
What can I do if my product is listed as "Will not fix"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
What can I do if my product is listed as "Fix deferred"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
- Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
My product is listed as "Out of Support Scope". What does this mean?
Not sure what something means? Check out our Security Glossary.