CVE-2026-13322 | Kubevirt: virt-handler-rhel9: kubevirt: unbounded virtio-serial readline in virt-handler causes oom denial of service

A flaw was found in KubeVirt's downward metrics virtio-serial server. The server reads guest requests using textproto.Reader.ReadLine(), which buffers input indefinitely until a newline character is received, with no length limit or read deadline. A user with access to a VM guest that has the downward metrics virtio-serial device configured can write a continuous byte stream to the device, causing unbounded memory allocation in the virt-handler process until it is OOM-killed.

Published: 2026-06-25 Last update: 2026-06-26 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-13322 is rated Low Risk (15.5/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.10%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-13322

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-26 0.10%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-13322

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.8 3.1 LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:L Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
2.0 1.4 [email protected]

Weakness enumeration for CVE-2026-13322

GitHub Security Advisory for CVE-2026-13322

GHSA-6f2p-2qg2-qqch · Severity: low — A flaw was found in KubeVirt's downward metrics virtio-serial server. The server reads guest...

OS Trackers for CVE-2026-13322

Affected software / configurations for CVE-2026-13322

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-13322

cvelogic Threat Intelligence