CVE-2024-40647 is a medium-severity (CVSS 5.3) Information Exposure vulnerability in sentry-sdk. A fix is available for sentry-sdk — see the affected versions and patch details below.
Unintentional exposure of environment variables to subprocesses in sentry-sdk
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-40647.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2024-40647 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
sentry-sdk🐍sentry-sdkReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Impact
The bug in Sentry's Python SDK <2.8.0 results in the unintentional exposure of environment variables to subprocesses despite the env={} setting.
Details
In Python's subprocess calls, all environment variables are passed to subprocesses by default. However, if you specifically do not want them to be passed to subprocesses, you may use env argument in subprocess calls, like in this example:
>>> subprocess.check_output(["env"], env={"TEST":"1"})
b'TEST=1\n'
If you'd want to not pass any variables, you can set an empty dict:
>>> subprocess.check_output(["env"], env={})
b''
However, the bug in Sentry SDK <2.8.0 causes all environment variables to be passed to the subprocesses when env={} is set, unless the Sentry SDK's Stdlib integration is disabled. The Stdlib integration is enabled by default.
Patches
The issue has been patched in https://github.com/getsentry/sentry-python/pull/3251 and the fix released in sentry-sdk==2.8.0. The fix was also backported to sentry-sdk==1.45.1.
Workarounds
We strongly recommend upgrading to the latest SDK version. However, if it's not possible, and if passing environment variables to child processes poses a security risk for you, there are two options:
- In your application, replace
env={}with the minimal dictenv={"EMPTY_ENV":"1"}or similar.
OR
- Disable Stdlib integration:
import sentry_sdk
# Should go before sentry_sdk.init
sentry_sdk.integrations._DEFAULT_INTEGRATIONS.remove("sentry_sdk.integrations.stdlib.StdlibIntegration")
sentry_sdk.init(...)
References
- Sentry docs: Default integrations
- Python docs: subprocess module
- Patch https://github.com/getsentry/sentry-python/pull/3251
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | sentry-sdk | ≥ 2.0.0a1&&< 2.8.0 | 2.8.0pip install --upgrade 'sentry-sdk==2.8.0' |
| 🐍PyPI | sentry-sdk | all versions | 1.45.1pip install --upgrade 'sentry-sdk==1.45.1' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sentry-sdk, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update sentry-sdk to 2.8.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-40647 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-40647 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-40647. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-40647 in your dependencies?
O3 Security finds CVE-2024-40647 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.