How severe is CVE-2026-44502?

CVE-2026-44502 has a CVSS score of 4.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-44502?

CVE-2026-44502 affects the following packages: bugsink (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-44502?

Update bugsink to 2.1.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44502 is resolved across your whole dependency graph.

How do I detect CVE-2026-44502 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for bugsink, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-44502 if there is no patch (or I can't update yet)?

Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Is CVE-2026-44502 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-44502 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-44502?

CVE-2026-44502 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 21th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-44502?

CVE-2026-44502 is classified as Server-Side Request Forgery (SSRF) (CWE-918). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-44502 published, and has it been updated?

CVE-2026-44502 was published on May 26, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

MEDIUM severity

CVE-2026-44502 — bugsink

MEDIUMFix: bugsink/bugsink@940d2df

CVE-2026-44502 is a medium-severity (CVSS 4.3) Server-Side Request Forgery (SSRF) vulnerability in bugsink. A fix is available for bugsink — see the affected versions and patch details below.

Bugsink: SSRF bypass in `validate_webhook_url`

Also known asGHSA-fp53-qcf8-2xx2PYSEC-2026-2405

Published

May 26, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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-2026-44502.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs21th percentile — riskier than 21% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐍bugsink

Real-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

Summary

Bugsink’s webhook URL validation in versions 2.1.2 and earlier could be (partially) bypassed because of a mismatch in URL parsing.

In some malformed URLs, Python’s standard URL parser (urllib) and the HTTP client stack (requests / urllib3) do not agree on which host is actually being targeted. That could allow a webhook URL to pass Bugsink’s outbound-host checks while the actual HTTP request is sent somewhere else.

Impact

This issue affects Bugsink’s outbound webhook integrations.

An attacker who can supply or influence a webhook URL may be able to make Bugsink send an outbound HTTP POST request to a host that should have been blocked by the webhook validation logic, including loopback, private, or otherwise non-allowlisted destinations.

The practical impact is limited:

this is an outbound webhook SSRF issue, not a general-purpose proxy
Bugsink does not follow redirects for these webhook requests
the request shape is constrained by how the malformed URL is normalized by the HTTP client
this does not give arbitrary control over every possible request path

In other words, this is a real validation bypass, but it is narrower than a full arbitrary-request primitive.

Technical Details

The original validation logic parsed webhook URLs with Python’s urllib.parse.urlparse, then sent the request with requests.post.

For malformed inputs involving backslashes and @, those components can disagree about where the authority ends and which hostname is the real target. A URL may therefore appear to target an allowlisted public hostname during validation, while the HTTP client actually connects to a different host.

Fix

The fix has two parts:

Bugsink now normalizes webhook URLs using the same HTTP client stack that will later send them, and applies validation to that normalized form.
Bugsink now outright rejects raw webhook URLs containing characters outside the RFC URL character set, rather than relying on downstream normalization of malformed input.

Together, these changes remove the parser discrepancy and make webhook URL handling stricter and more predictable.

Workarounds

If users cannot upgrade immediately:

restrict who can configure or modify webhook URLs
review existing webhook configurations for malformed or unusual URLs
prefer tightly controlled outbound network policy at the deployment level

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`bugsink`	all versions	2.1.3`pip install --upgrade 'bugsink==2.1.3'`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for bugsink, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update bugsink to 2.1.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44502 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Frequently Asked Questions

## Summary Bugsink’s webhook URL validation in versions 2.1.2 and earlier could be (partially) bypassed because of a mismatch in URL parsing. In some malformed URLs, Python’s standard URL parser (urllib) and the HTTP client stack (requests / urllib3) do not agree on which host is actually being targeted. That could allow a webhook URL to pass Bugsink’s outbound-host checks while the actual HTTP request is sent somewhere else. ## Impact This issue affects Bugsink’s outbound webhook integrations. An attacker who can supply or influence a webhook URL may be able to make Bugsink send an outb