Cyber Resilience

CVE-2026-26269

Memory Safety in Vim ≤ 9.1.2148

Memory Safety
Published
13 February 2026
Modified
18 February 2026
Patch / advisory
View advisory
CVSS Score v3.1 5.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
EPSS Score 0.0028 21th percentile
Risk Priority 43 floored blend · peak EPSS

Summary

CVE-2026-26269 is a medium-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Vim Vim. Its CVSS base score is 5.4 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 21th 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 SI-10 (Information Input Validation) — 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-2026-26269 is a stack buffer overflow vulnerability in Vim, an open source command-line text editor. It affects Vim versions prior to 9.1.2148 that have the NetBeans integration feature enabled and in use. The flaw resides in the special_keys() function within src/netbeans.c, where a while (*tok) loop writes two bytes per iteration into a fixed 64-byte stack buffer named keybuf without performing bounds checks. This allows overflow via a specially crafted specialKeys command.

An attacker can exploit this vulnerability by operating a malicious NetBeans server to which a victim connects using a vulnerable Vim instance. Exploitation requires network access to the server, low attack complexity, no privileges, and user interaction, such as the user manually connecting Vim to the attacker's NetBeans server. Successful exploitation can result in limited integrity and availability impacts, with a CVSS v3.1 base score of 5.4 (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L), potentially leading to memory corruption, denial of service, or limited code manipulation depending on the context.

The vulnerability has been addressed in Vim patch v9.1.2148, as detailed in the official GitHub commit c5f312aad8e4179e437f81ad39a860cd0ef11970, the release page for v9.1.2148, and the security advisory GHSA-9w5c-hwr9-hc68. Security practitioners should update to Vim 9.1.2148 or later and disable NetBeans integration if not required, with further discussion available on the oss-security mailing list from February 13, 2026.

EU & UK References

Vulnerability Data

Vim is an open source, command line text editor. Prior to 9.1.2148, a stack buffer overflow vulnerability exists in Vim's NetBeans integration when processing the specialKeys command, affecting Vim builds that enable and use the NetBeans feature. The Stack buffer…

more

overflow exists in special_keys() (in src/netbeans.c). The while (*tok) loop writes two bytes per iteration into a 64-byte stack buffer (keybuf) with no bounds check. A malicious NetBeans server can overflow keybuf with a single specialKeys command. The issue has been fixed as of Vim patch v9.1.2148.

CWE(s)
CWE-121

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.
attack.mitre.org →
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.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-28422Same product: Vim Vim
CVE-2023-1175Same product: Vim Vim
CVE-2025-55157Same product: Vim Vim
CVE-2023-46246Same product: Vim Vim
CVE-2023-0051Same product: Vim Vim
CVE-2023-0433Same product: Vim Vim
CVE-2023-2426Same product: Vim Vim
CVE-2023-48706Same product: Vim Vim
CVE-2023-1170Same product: Vim Vim
CVE-2023-0288Same product: Vim Vim

Affected Assets

vim
vim
≤ 9.1.2148

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and analysis can discover stack-buffer overflows before deployment.

SI-10 Information Input Validation good match

Input validation directly stops untrusted data from exceeding stack buffer bounds.

SI-16 Memory Protection good match

Memory-protection mechanisms limit the ability to execute injected code after a stack overflow.

SA-8 Security and Privacy Engineering Principles partial match

Secure-engineering principles include bounds-checked coding and safe buffer handling that avoid introducing the flaw.

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 directly prevent introduction of stack buffer overflows.

ID.RA-01 partial match
prevents

Vulnerability scanning can discover stack buffer overflows but does not prevent their introduction.

PR.PS-02 partial match
prevents

Patching eliminates known instances of the weakness after discovery.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing (fuzzing, static analysis) detects stack overflows before release.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates buffer-safety practices that directly prevent stack overflows.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify buffer-size and input-validation rules.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles include memory-safety and least-privilege stack usage.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid unsafe buffer handling that causes CWE-121.

A.8.32 Change management none match
none

Change-management gates can enforce security reviews that catch buffer issues.

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-248594 OL 8 must implement address space layout randomization (ASLR) to protect its memory from unauthorized code execution. prevents CWE-121
Oracle Linux 9 (1 rule)
  • V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-121

References