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

ipvs: avoid out-of-bounds write in ip_vs_nat_icmp

Sashiko warns that local attacker can modify the packet
while it is processed by IPVS. Some places read the
IP ihl field multiple times which can cause out-of-bounds
access. One such place is ip_vs_nat_icmp where we
can write after the validated area.

Fix it by providing ciph argument just like it is done for
IPv6 and use ciph->len as offset to the embedded transport
header.

Modify some IPv4 header checks by reading the ihl field
only once.
Published: 2026-08-22
Score: 7.8 High
EPSS: < 1% Very Low
KEV: No
Impact: Local Code Execution
Action: Patch Immediately
AI Analysis

Impact

The Linux kernel contains an out‑of‑bounds write flaw in the IPVS NAT ICMP handling function. When specific ICMP packets are processed, the kernel may write beyond the intended memory region, corrupting arbitrary memory. This vulnerability can lead to local code execution or a denial‑of‑service. The weakness is a classic out‑of‑bounds write, identified by CWE‑120 and CWE‑787.

Affected Systems

The flaw resides in the IPVS module of the Linux kernel. Any system running a kernel version that has not yet incorporated the patch, and that has IPVS enabled, is potentially affected. No explicit kernel version numbers are disclosed in the advisory, so all affected kernel releases that still contain the unpatched ip_vs_nat_icmp code should be considered vulnerable.

Risk and Exploitability

The CVSS score of 7.8 classifies the flaw as high severity, indicating that a successful exploit could have a serious impact on system integrity and availability. The EPSS score is below 1%, suggesting that exploitation is unlikely to be widespread or automated at present. The vulnerability is not listed in the CISA KEV catalog, but the low exploitation probability does not diminish the need for immediate mitigation. As described, a local attacker who can send ICMP packets that IPVS processes can abuse the out‑of‑bounds write in ip_vs_nat_icmp to corrupt memory, potentially enabling local code execution or a kernel crash, leading to denial of service. Because the attack surface is tied to the presence of IPVS and the ability to send crafted ICMP packets to the host, the risk is limited to hosts that run IPVS and accept such traffic, but the impact remains severe for affected systems.

Generated by OpenCVE AI on August 25, 2026 at 09:27 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply a kernel update that includes the commit that fixes ip_vs_nat_icmp handling
  • If an update cannot be applied immediately, temporarily disable IPVS or the NAT ICMP feature in the kernel configuration
  • Monitor kernel logs for out‑of‑bounds write warnings and restrict IPVS traffic through network segmentation or firewalls

Generated by OpenCVE AI on August 25, 2026 at 09:27 UTC.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4777-1 linux security update
Debian DSA Debian DSA DSA-6466-1 linux security update
History

Tue, 25 Aug 2026 12:15:00 +0000


Tue, 25 Aug 2026 09:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119
CWE-787

Tue, 25 Aug 2026 08:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-120
CWE-787

Tue, 25 Aug 2026 06:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Sat, 22 Aug 2026 19:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-120
CWE-787

Sat, 22 Aug 2026 15:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: ipvs: avoid out-of-bounds write in ip_vs_nat_icmp Sashiko warns that local attacker can modify the packet while it is processed by IPVS. Some places read the IP ihl field multiple times which can cause out-of-bounds access. One such place is ip_vs_nat_icmp where we can write after the validated area. Fix it by providing ciph argument just like it is done for IPv6 and use ciph->len as offset to the embedded transport header. Modify some IPv4 header checks by reading the ihl field only once.
Title ipvs: avoid out-of-bounds write in ip_vs_nat_icmp
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: 2026-08-25T05:42:04.705Z

Reserved: 2026-08-15T05:44:03.929Z

Link: CVE-2026-74724

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-22T16:16:47.450

Modified: 2026-08-25T06:18:58.390

Link: CVE-2026-74724

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-22T00:00:00Z

Links: CVE-2026-74724 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-25T09:30:05Z

Weaknesses
  • CWE-119

    Improper Restriction of Operations within the Bounds of a Memory Buffer

  • CWE-787

    Out-of-bounds Write