Cyber Resilience

CVE-2026-46300

Memory Safety in Linux Kernel 3.9 – 5.10.257

Published
23 May 2026
Modified
23 July 2026
Patch / advisory
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.070 94th percentile
Risk Priority 64 floored blend · peak EPSS

Summary

CVE-2026-46300 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Linux Linux Kernel. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-16 (Memory Protection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

In the Linux kernel, the following vulnerability has been resolved: net: skbuff: preserve shared-frag marker during coalescing skb_try_coalesce() can attach paged frags from @from to @to. If @from has SKBFL_SHARED_FRAG set, the resulting @to skb can contain the same externally-owned…

more

or page-cache-backed frags, but the shared-frag marker is currently lost. That breaks the invariant relied on by later in-place writers. In particular, ESP input checks skb_has_shared_frag() before deciding whether an uncloned nonlinear skb can skip skb_cow_data(). If TCP receive coalescing has moved shared frags into an unmarked skb, ESP can see skb_has_shared_frag() as false and decrypt in place over page-cache backed frags. Propagate SKBFL_SHARED_FRAG when skb_try_coalesce() transfers paged frags. The tailroom copy path does not need the marker because it copies bytes into @to's linear data rather than transferring frag descriptors.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-43500Same product: Linux Linux Kernel
CVE-2023-52775Same product: Linux Linux Kernel
CVE-2024-42288Same product: Linux Linux Kernel
CVE-2023-52868Same product: Linux Linux Kernel
CVE-2024-41042Same product: Linux Linux Kernel
CVE-2024-42236Same product: Linux Linux Kernel
CVE-2025-21865Same product: Linux Linux Kernel
CVE-2024-56614Same product: Linux Linux Kernel
CVE-2024-44938Same product: Linux Linux Kernel
CVE-2024-50288Same product: Linux Linux Kernel

Affected Assets

linux
linux kernel
7.1 · 3.9 — 5.10.257 · 5.11 — 5.15.208 · 5.16 — 6.1.174

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 4 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (including fuzzing and bounds checks) finds out-of-bounds write flaws before deployment.

Memory-protection mechanisms block unauthorized writes to arbitrary locations even if a write-what-where primitive exists.

Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.

Secure engineering principles require memory-safe coding and bounds checking that eliminate the root cause of write-what-where flaws.

Process isolation confines the blast radius of an arbitrary write so it cannot affect other domains.

Input validation can structurally reject or sanitize data that would otherwise trigger an out-of-bounds write.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices (static analysis, bounds checking, code review) are the primary means of preventing out-of-bounds writes.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.

PR.PS-02 partial match
prevents

Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development and acceptance can detect and prevent out-of-bounds write defects.

prevents

Secure development life cycle mandates practices that prevent out-of-bounds writes.

prevents

Application security requirements can specify bounds-checking and safe memory handling.

prevents

Secure architecture and engineering principles reduce the likelihood of buffer overflows.

prevents

Secure coding directly addresses out-of-bounds writes through language choice and coding standards.

prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248592 OL 8 must clear memory when it is freed to prevent use-after-free attacks. prevents CWE-123
RHEL 8 (1 rule)
  • V-230279 RHEL 8 must clear memory when it is freed to prevent use-after-free attacks. prevents CWE-123
Windows 10 (1 rule)
  • V-220727 Structured Exception Handling Overwrite Protection (SEHOP) must be enabled. prevents CWE-123
Windows 11 (1 rule)
  • V-253284 Structured Exception Handling Overwrite Protection (SEHOP) must be enabled. prevents CWE-123

References