TI-2025-39901 Aliases CVE-2025-64509 GHSA-rrx3-2x4g-mq2h

Bugsink vulnerable to unauthenticated remote DoS via crafted Brotli input (via CPU)

LOW 39CWE-770Published 2025-11-10 · Updated 2025-11-12

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-770.

Summary

Bugsink is a self-hosted error tracking tool. In versions prior to 2.0.6, a specially crafted Brotli-compressed envelope can cause Bugsink to spend excessive CPU time in decompression, leading to denial of service. This can be done if the DSN is known, which it is in many common setups (JavaScript, Mobile Apps). The issue is patched in Bugsink 2.0.6. The vulnerability is similar to, but distinct from, another brotli-related problem in Bugsink, GHSA-fc2v-vcwj-269v/CVE-2025-64508.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00337 27th percentileScored 2026-11-07

Fix Fixed bugsink (bugsink): 2.0.6bugsink (PyPI): 2.0.6

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
bugsink	bugsink	before 2.0.6	2.0.6	Patch available	CNA
—	bugsink (PyPI)	before 2.0.6	2.0.6	Patch available	GHSA-rrx3-2x4g-mq2h

bugsink Vendorbugsink Affected before 2.0.6 Fixed in 2.0.6 Patch available CNA
bugsink (PyPI) Vendor— Affected before 2.0.6 Fixed in 2.0.6 Patch available GHSA-rrx3-2x4g-mq2h

Remediation

Fix · CNA bugsink (bugsink) Fixed in 2.0.6
Fix · GHSA-rrx3-2x4g-mq2h bugsink (PyPI) Fixed in 2.0.6 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2025-64509
2026-10-03 Alias added: GHSA-rrx3-2x4g-mq2h

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2025-64509

Other 3

TI-2026-22000 Bugsink is vulnerable to Stored XSS via Pygments fallback in stacktrace rendering CVSS 3.1CRITICAL 9.3
TI-2025-39900 Bugsink vulnerable to unauthenticated remote DoS via crafted Brotli input CVSS 3.1HIGH 7.5
TI-2025-34236 Bugsink is vulnerable to Path Traversal attacks via event_id in ingestion CVSS 4.0HIGH 7.2
TI-2026-28977 Bugsink affected by authenticated arbitrary file write in artifactbundle/assemble CVSS 3.1HIGH 7.1
TI-2026-38922 Bugsink: DOS using large numbers of event tags CVSS 3.1MEDIUM 4.3
TI-2026-32436 Bugsink: SSRF bypass in `validate_webhook_url` CVSS 3.1MEDIUM 4.3

See all 9 →

Sources

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