How severe is CVE-2025-64509?

CVE-2025-64509 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2025-64509 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-64509?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-64509 have an EU (EUVD) identifier?

Yes. CVE-2025-64509 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-50819.

When was CVE-2025-64509 published?

CVE-2025-64509 was published on 2025-11-10 and last updated on 2026-06-17.

CVE-2025-64509

CVE-2025-64509 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-770.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-50819
Weakness: CWE-770
Published: 2025-11-10
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2025-64509?: 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.
How severe is CVE-2025-64509?: CVE-2025-64509 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-64509 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-64509?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-64509 have an EU (EUVD) identifier?: Yes. CVE-2025-64509 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-50819.
When was CVE-2025-64509 published?: CVE-2025-64509 was published on 2025-11-10 and last updated on 2026-06-17.

References

https://github.com/bugsink/bugsink/security/advisories/GHSA-rrx3-2x4g-mq2h

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