VulnerabilityPublished 20 Oct 2026

CVE-2026-113731: djust · Path Traversal

Affects djustSource CVE Database V5

Not known to be exploited · CVSS 3.3 Low · fixed in 1.3.0rc8 : update djust when convenient.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

3.3Low

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.3.0rc8, 1.2.4, 1.1.7 +1

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

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

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
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: 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: 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: None: There is no loss of integrity within 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 20 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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 djust and djust-org/djust to 1.3.0rc8, 1.2.4, 1.1.7 or 1.0.10.

Affected software

Product	Affected	Fixed in
djust-orgdjust	Affected >=1.3.0.dev0 <1.3.0rc8	Fixed in 1.3.0rc8
djust-orgdjust	Affected >=1.2.0.dev0 <1.2.4	Fixed in 1.2.4
djust-orgdjust	Affected >=1.1.0 <1.1.7	Fixed in 1.1.7
djust-orgdjust	Affected >=0.9.0 <1.0.10	Fixed in 1.0.10
GitHubdjust-org/djust`pkg:github/djust-org/djust`Other threats	Affected >=0.9.0 <1.0.10 >=1.1.0 <1.1.7 >=1.2.0.dev0 <1.2.4 >=1.3.0.dev0 <1.3.0rc8	Fixed in 1.0.10 1.1.7 1.2.4 1.3.0rc8

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

AI-suggested

Upgrade djust to versions 1.0.10, 1.1.7, 1.2.4, or 1.3.0rc8 or later where the vulnerability is fixed. Since the MCP server communicates only over local stdio and runs as the same OS user, restricting local access to trusted users also mitigates risk.

Description

### Affected version / file / line Version: djust v1.1.4 (latest release, published 2026-09-23). File: python/djust/mcp/server.py:354-433 (MCP tool find_handlers_for_template). Confirmed identical on the commit used for triage, a7e4fafd1667b4db0b1465652d4a63cb17117a07. ### Description ``` @mcp.tool() def find_handlers_for_template(template_path: str) -> str: """ Args: template_path: Either a logical template name (e.g. 'demos/counter.html' — what you'd pass to `render`) OR an absolute filesystem path. Both are searched. """ ... resolved_path: str | None = None if os.path.isabs(template_path) and os.path.isfile(template_path): resolved_path = template_path else: ... # logical-name resolution via Django's template loader ... with open(resolved_path, "r", encoding="utf-8", errors="replace") as f: source = f.read() handler_names_in_template = sorted({m.group(2) for m in dj_event_attr_re.finditer(source)}) ``` When template_path is an absolute path to an existing file, it is used directly, with no confinement to the project/template directories — no realpath() + prefix check, no allowlist. open(resolved_path, ...) then reads the file. This is inconsistent with the sibling tool in the same file (loaddata, ~line 290-303), which explicitly rejects paths outside the project directory for its own path-like parameter: ``` candidate = os.path.realpath(...) if base_dir and not candidate.startswith(os.path.realpath(str(base_dir))): return json.dumps({"error": f"fixture path '{p}' resolves outside the project directory", ...}) ``` find_handlers_for_template has no equivalent check for template_path before the open() call. ### Impact An MCP client with access to this tool (available whenever the Django project is running the MCP server via python manage.py djust_mcp — no separate opt-in flag gates this specific tool beyond that) can read the contents of any file on disk that the process has read permission to and that exists, by passing an absolute path — e.g. /etc/passwd, application .env files, SSH keys, or any other sensitive file reachable by the server process's user. Mitigating factor (reduces this from High to Medium): the tool does not return the raw file content. It runs one fixed regex (dj-(?:click|submit|change|input|keydown|keyup)\s*=\s*['"]([^'"]+)['"]) against the content and returns only the matched handler-name strings, plus confirmation that the file exists and is readable (an existence/readability oracle on its own, independent of the regex match). If the targeted file happens to contain text matching that HTML-attribute-like pattern (plausible for config files, logs, or any text file with key="value"-shaped content), those substrings are returned in full — so the read is not purely blind, but it is not a general-purpose arbitrary-file-read primitive either. Proof of Concept / Reproduction Traced via direct source read; no live Django project was exercised for this report (would require a full djust project scaffold, which was out of scope for this pass — see limitation below). 1. MCP client calls: find_handlers_for_template(template_path="/etc/passwd") 2. server.py ~line 393: ``` if os.path.isabs(template_path) and os.path.isfile(template_path): resolved_path = template_path ``` resolved_path == "/etc/passwd", unchanged, unconfined 3. server.py ~line 430: ``` with open(resolved_path, "r", encoding="utf-8", errors="replace") as f: source = f.read() ``` /etc/passwd is now fully read into `source` 4. The regex dj_event_attr_re.finditer(source) is applied to the real /etc/passwd content. /etc/passwd will not match this specific pattern, so the response would report an empty handler list plus "file exists and was read" - which already confirms the path-confinement bypass (compare with passing a nonexistent absolute path, which correctly returns "Template file not found"). 5. On a target where the absolute path points to a file that DOES contain text shaped like `dj-click="..."` (e.g. a copied HTML fragment, a stray config value, or a crafted file placed by the attacker via another vector), the matched substrings are returned verbatim in the JSON response - full-content disclosure of just those substrings, not the whole file. ### Suggested Fix Apply the same confinement loaddata already uses, before the os.path.isfile check: ``` if os.path.isabs(template_path): candidate = os.path.realpath(template_path) if base_dir and not candidate.startswith(os.path.realpath(str(base_dir))): return json.dumps({ "error": f"template path '{template_path}' resolves outside the project directory", "resolved": candidate, "project_dir": str(base_dir), }) if os.path.isfile(candidate): resolved_path = candidate ``` ### Limitations Not exercised against a live Django/dju

Impact

An attacker with local access to the MCP tool can probe the file system for readable files and extract specific substrings matching dj-* attribute patterns. This may disclose limited information about file contents but does not allow arbitrary file content disclosure or remote exploitation. The vulnerability has no network exposure and requires local privileges. The CVSS score is 3.3 (low), reflecting limited confidentiality impact and no integrity or availability impact.

Summary

The djust package, which provides Phoenix LiveView-style reactive server-side rendering for Django, contains a path traversal vulnerability in its MCP tool find_handlers_for_template located in python/djust/mcp/server.py. From versions 0.9.0 until 1.0.10, 1.1.7, 1.2.4, and 1.3.0rc8, the tool accepts an absolute template_path and reads files without restricting the resolved path to the project or configured template directories. This allows a local MCP client, communicating over local stdio as the same OS user, to use the tool as a file existence and readability oracle and extract substrings matching certain dj-* attribute patterns from files readable by the djust process. The tool does not return arbitrary raw file contents and has no network listener. The vulnerability is fixed in versions 1.0.10, 1.1.7, 1.2.4, and 1.3.0rc8.

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 20 Oct 2026, 22:03 UTC

WeaknessesCWE-22

Technical details

References

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