VulnerabilityPublished 26 Feb 2026

CVE-2026-27884: Pennyw0rth NetExec · Path Traversal

Affects Pennyw0rth NetExecSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium : upgrade to 1.5.1 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 32% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.5.1

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 26 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade NetExec and pennyw0rth/NetExec to 1.5.1.

Affected software

Product	Affected	Fixed in
Pennyw0rthNetExec	Affected <1.5.1	Fixed in 1.5.1
GitHubpennyw0rth/NetExec`pkg:github/pennyw0rth/NetExec`Other threats	Affected <1.5.1	Fixed in 1.5.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2026-27884, organizations should immediately upgrade Pennyw0rth NetExec to version 1.5.1 or later, where the vulnerability has been patched. Until patching is possible, avoid running the spider_plus module with DOWNLOAD=true against SMB shares, especially those that are untrusted or external. Implement strict access controls and monitoring on SMB shares to prevent attackers from placing malicious filenames containing path traversal sequences. Employ network segmentation to limit exposure of NetExec systems to potentially hostile SMB shares. Additionally, consider auditing and restricting the directories where spider_plus saves files to prevent unauthorized file overwrites. Monitoring file integrity on systems running NetExec can help detect suspicious modifications. Finally, educate users and administrators about the risks of running automated SMB crawlers against untrusted sources and enforce policies to reduce risky configurations.

Description

NetExec is a network execution tool. Prior to version 1.5.1, the module spider_plus improperly creates the output file and folder path when saving files from SMB shares. It does not take into account that it is possible for Linux SMB shares to have path traversal characters such as `../` in them. An attacker can craft a filename in an SMB share that includes these characters, which when spider_plus crawls and downloads, can write or overwrite arbitrary files. The issue is patched in v1.5.1. As a workaround, do not run spider_plus with DOWNLOAD=true against targets.

Impact

The primary impact of CVE-2026-27884 is the unauthorized modification or overwriting of files on systems running vulnerable versions of NetExec when spider_plus is used to download files from SMB shares. This can lead to integrity violations, such as replacing configuration files, scripts, or binaries, potentially enabling further compromise or disruption of operations. While confidentiality and availability are not directly affected, the ability to alter files arbitrarily can facilitate privilege escalation, persistence, or sabotage. Organizations relying on NetExec for automated SMB crawling and file retrieval are at risk, especially if they interact with untrusted or external SMB shares. The attack complexity is high due to the need for user interaction and specific configuration, which somewhat limits widespread exploitation. However, targeted attacks against organizations using vulnerable versions could result in significant operational and security consequences. The lack of known exploits in the wild suggests limited current exploitation but does not preclude future attacks once the vulnerability is publicly known.

CWE-22Improper Limitation of a Pathname to a Restricted Directory (Path Traversal) (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #6OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.1 (opens in a new tab)
Attack patterns
Path Traversal (opens in a new tab)
Using Slashes and URL Encoding Combined to Bypass Validation Logic (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
Using Escaped Slashes in Alternate Encoding (opens in a new tab)
Using Slashes in Alternate Encoding (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 5 Mar 2026, 11:14 UTC

Public exploits and detectionGitHub proofs of concept

WeaknessesCWE-22

Technical details

References

Community reviews

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