Description
In the Linux kernel, the following vulnerability has been resolved:

RDMA/core: Prefer NLA_NUL_STRING

These attributes are evaluated as c-string (passed to strcmp), but
NLA_STRING doesn't check for the presence of a \0 terminator.

Either this needs to switch to nla_strcmp() and needs to adjust printf fmt
specifier to not use plain %s, or this needs to use NLA_NUL_STRING.

As the code has been this way for long time, it seems to me that userspace
does include the terminating nul, even tough its not enforced so far, and
thus NLA_NUL_STRING use is the simpler solution.
Published: 2026-07-19
Score: 8.4 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The flaw in the Linux kernel’s RDMA core module treats Netlink attributes of type NLA_STRING as plain C strings without validating the terminating NUL character. When the code passes these attributes to functions like strcmp and printf with a %s specifier, a crafted payload that lacks a null terminator causes the kernel to read beyond the allocated buffer, creating an out-of-bounds read that can lead to kernel memory corruption. This weakness matches CWE‑125 and is limited to the RDMA messaging subsystem.

Affected Systems

All Linux kernel releases containing the legacy RDMA core code that has not applied the NLA_NUL_STRING patch are vulnerable. The issue exists across all current releases that still handle NLA_STRING in the same unprotected way. Any system running a kernel with that unpatched logic—particularly those using RDMA for network or storage traffic—is at risk. No specific version range is identified, so all current kernel distributions that have not incorporated the patch are susceptible.

Risk and Exploitability

The CVSS score of 8.4 reflects a high severity impact. The EPSS score of less than 1 % indicates that exploitation of this flaw is currently uncommon. An attacker would need the ability to inject malformed Netlink messages, which typically requires local or elevated privileges, or a compromised RDMA client that can send crafted attributes. While the vulnerability is not listed in CISA’s KEV catalog, the kernel’s privileged nature means a successful exploitation could allow privilege escalation to kernel level.

Generated by OpenCVE AI on August 4, 2026 at 07:04 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Update the Linux kernel to a version that includes the NLA_NUL_STRING patch for the RDMA core.
  • If a patched kernel is not available, manually apply the commit that changes NLA_STRING handling to NLA_NUL_STRING or uses nla_strcmp() in the affected source files.
  • If upgrading or patching is infeasible, disable or unload the RDMA core module and restrict Netlink access to trusted users to prevent malformed attribute injection.

Generated by OpenCVE AI on August 4, 2026 at 07:04 UTC.

Tracking

Sign in to view the affected projects.

Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-8574-1 Linux kernel (GCP FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8576-1 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8593-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8574-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8595-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-8596-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8576-2 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8595-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8603-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8606-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8607-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8608-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8609-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8610-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8574-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8595-3 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8618-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8619-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-2 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-3 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-4 Linux kernel (Intel IoTG) vulnerabilities
History

Wed, 22 Jul 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-125
References
Metrics threat_severity

None

threat_severity

Moderate


Mon, 20 Jul 2026 14:45:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 8.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Sun, 19 Jul 2026 14:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: RDMA/core: Prefer NLA_NUL_STRING These attributes are evaluated as c-string (passed to strcmp), but NLA_STRING doesn't check for the presence of a \0 terminator. Either this needs to switch to nla_strcmp() and needs to adjust printf fmt specifier to not use plain %s, or this needs to use NLA_NUL_STRING. As the code has been this way for long time, it seems to me that userspace does include the terminating nul, even tough its not enforced so far, and thus NLA_NUL_STRING use is the simpler solution.
Title RDMA/core: Prefer NLA_NUL_STRING
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-05T12:36:38.134Z

Reserved: 2026-07-19T07:54:57.017Z

Link: CVE-2026-63860

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-07-19T00:00:00Z

Links: CVE-2026-63860 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-04T07:15:03Z

Weaknesses