VulnerabilityPublished 13 Mar 2026

CVE-2026-31886: dagu · Path Traversal

Affects daguSource CVE Database V5

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Not known to be exploited · CVSS 9.1 Critical : upgrade to 2.2.4 as a priority.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

9.1Critical

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

Contested

Critical score, yet low EPSS after six months

EPSS: 0.4% chance of exploitation in 30 days – higher than 37% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.2.4

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

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

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: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
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), 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 dagu and dagu-org/dagu to 2.2.4.

Affected software

Product	Affected	Fixed in
dagu-orgdagu	Affected <2.2.4	Fixed in 2.2.4
GitHubdagu-org/dagu`pkg:github/dagu-org/dagu`Other threats	Affected <2.2.4	Fixed in 2.2.4

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-2026-31886, organizations should immediately upgrade dagu to version 2.2.4 or later, where the vulnerability is fixed. If upgrading is not immediately possible, implement strict input validation and sanitization on the dagRunId parameter to prevent path traversal sequences such as '..'. Employ application-layer filtering or web application firewalls (WAFs) to detect and block malicious requests attempting directory traversal. Run dagu with the least privilege possible, avoiding root or overly permissive container configurations to limit the scope of damage if exploited. Regularly monitor logs for unusual deletion activity or errors related to temporary directories. Implement file system protections such as immutable flags or access control lists (ACLs) on critical directories like /tmp to prevent unauthorized deletions. Finally, conduct thorough testing of workflow engine endpoints to ensure no other parameters allow similar traversal or destructive operations.

Description

Dagu is a workflow engine with a built-in Web user interface. Prior to 2.2.4, the dagRunId request field accepted by the inline DAG execution endpoints is passed directly into filepath.Join to construct a temporary directory path without any format validation. Go's filepath.Join resolves .. segments lexically, so a caller can supply a value such as ".." to redirect the computed directory outside the intended /tmp/<name>/<id> path. A deferred cleanup function that calls os.RemoveAll on that directory then runs unconditionally when the HTTP handler returns, deleting whatever directory the traversal resolved to. With dagRunId set to "..", the resolved directory is the system temporary directory (/tmp on Linux). On non-root deployments, os.RemoveAll("/tmp") removes all files in /tmp owned by the dagu process user, disrupting every concurrent dagu run that has live temp files. On root or Docker deployments, the call removes the entire contents of /tmp, causing a system-wide denial of service. This vulnerability is fixed in 2.2.4.

Impact

The impact of CVE-2026-31886 is significant for organizations using dagu workflow engine versions prior to 2.2.4. Exploitation can lead to widespread denial of service by deleting critical temporary files or the entire /tmp directory, which many Linux-based systems and applications rely on for temporary storage. On non-root deployments, this disrupts all concurrent dagu runs, causing workflow failures and potential data loss in temporary processing. On root or containerized deployments, the deletion of /tmp can affect multiple system services and applications beyond dagu, potentially causing system instability or crashes. This can result in operational downtime, loss of productivity, and increased recovery costs. Although confidentiality and integrity impacts are limited, the availability impact is severe and can affect business continuity. The vulnerability can be exploited remotely with low complexity, increasing the risk of automated or widespread attacks. Organizations running dagu in critical environments, especially those using root or containerized deployments, face elevated risk of system-wide disruption.

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

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 Mar 2026, 19:59 UTC

WeaknessesCWE-22

Technical details

References

Community reviews

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