Raw vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-23098 is a high-severity Double Free (CWE-415) vulnerability in Linux Linux Kernel. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 7th percentile by exploit likelihood (below the median); 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 SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-23098 is a double-free vulnerability (CWE-415) in the Linux kernel's NET/ROM (netrom) implementation, specifically within the nr_route_frame() function. The issue arises because old_skb is freed immediately without checking if nr_neigh->ax25 is NULL; if it is NULL, the caller function frees old_skb again, resulting in a double-free. This affects Linux kernel versions prior to the application of the relevant stable patches.
An attacker on an adjacent network (AV:A) with low attack complexity (AC:L), no privileges (PR:N), and no user interaction (UI:N) can exploit this vulnerability, which has an unchanged scope (S:U) and high impacts on confidentiality, integrity, and availability (C:H/I:H/A:H), yielding a CVSS v3.1 base score of 8.8. Successful exploitation could lead to kernel memory corruption, potentially enabling denial of service, privilege escalation, or arbitrary code execution.
The provided kernel stable commit references detail the fix: patches modify nr_route_frame() to check whether nr_neigh->ax25 is NULL before freeing old_skb, preventing the double-free. Security practitioners should update to kernels incorporating these commits (e.g., 25aab6bfc310, 6e0110ea90313b7c0558a0b77038274a6821caf8, and others listed) and consider disabling NET/ROM if unused, as it is a niche protocol typically for amateur radio over AX.25.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-5444
Vulnerability Data
In the Linux kernel, the following vulnerability has been resolved: netrom: fix double-free in nr_route_frame() In nr_route_frame(), old_skb is immediately freed without checking if nr_neigh->ax25 pointer is NULL. Therefore, if nr_neigh->ax25 is NULL, the caller function will free old_skb again,…
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causing a double-free bug. Therefore, to prevent this, we need to modify it to check whether nr_neigh->ax25 is NULL before freeing old_skb.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 1 hardening rule · 1 OS baseline
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Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation explicitly includes dynamic analysis and fuzzing that locate double-free defects before release.
Security engineering principles can require memory-safe allocation patterns or language features that structurally eliminate double-free opportunities.
Flaw remediation processes require identification and correction of memory-management defects such as double free once discovered.
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.
Secure SDLC practices directly prevent double-free errors via static analysis, safe memory APIs, and testing.
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.
Security testing in development can detect double-free conditions before release.
Secure development life cycle includes memory-safety practices that can prevent double-free bugs.
Application security requirements can mandate memory-safety rules that reduce double-free risk.
Secure system architecture and engineering principles can prescribe safe memory-management patterns.
Secure coding standards directly address proper use of free() and similar functions.
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-248590 OL 8 must clear the page allocator to prevent use-after-free attacks. prevents CWE-415