CVE-2026-65609
Out-of-bounds write in nnn
Description
nnn is vulnerable to Out-of-Bound write vulnerability. Due to lack of validation of attacker-controlled length fields deserialized from a session file, a crafted session file can cause nnn to write data beyond the bounds of fixed-size global buffers when loaded with the -s option. An attacker who can place a malicious session file in the victim's nnn session directory can exploit this to corrupt adjacent global state. Maintainer of this project was notified about this vulnerability. It might has been addressed, but the maintainer did not provide a vulnerable version range. Only version 5.2 was tested and confirmed as vulnerable.
INFO
Published Date :
Aug. 19, 2026, 2:17 p.m.
Last Modified :
Aug. 19, 2026, 2:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-65609
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | LOW | 4bb8329e-dd38-46c1-aafb-9bf32bcb93c6 | ||||
| CVSS 4.0 | LOW | [email protected] |
Solution
- Update nnn to the latest stable version.
- Avoid loading untrusted session files.
- Validate session file integrity before loading.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-65609.
| URL | Resource |
|---|---|
| https://cert.pl/en/posts/2026/08/CVE-2026-65609 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-65609 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-65609
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-65609 vulnerability anywhere in the article.
-
cert.pl
Vulnerabilities in nnn software
Vulnerabilities in nnn software CVE ID CVE-2026-65609 Publication date 19 August 2026 Vendor nnn Product nnn Vulnerable versions 5.2 Vulnerability type (CWE) Out-of-bounds write (CWE-787) Report sourc ... Read more
The following table lists the changes that have been made to the
CVE-2026-65609 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 19, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/jarun/nnn', 'vendor': 'nnn', 'product': 'nnn', 'versions': [{'status': 'affected', 'version': '5.2', 'versionType': 'git'}], 'defaultStatus': 'unknown'}] Added Description nnn is vulnerable to Out-of-Bound write vulnerability. Due to lack of validation of attacker-controlled length fields deserialized from a session file, a crafted session file can cause nnn to write data beyond the bounds of fixed-size global buffers when loaded with the -s option. An attacker who can place a malicious session file in the victim's nnn session directory can exploit this to corrupt adjacent global state. Maintainer of this project was notified about this vulnerability. It might has been addressed, but the maintainer did not provide a vulnerable version range. Only version 5.2 was tested and confirmed as vulnerable. Added CVSS V4.0 AV:L/AC:L/AT:N/PR:L/UI:A/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-787 Added Reference https://cert.pl/en/posts/2026/08/CVE-2026-65609