CVE-2026-39847

CVE-2026-39847 is a critical-severity vulnerability in Emmett with a CVSS 3.x base score of 9.1. 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-22.

Key facts

Description

Emmett is a full-stack Python web framework designed with simplicity. From 2.5.0 to before 2.8.1, the RSGI static handler for Emmett's internal assets (/__emmett__ paths) is vulnerable to path traversal attacks. An attacker can use ../ sequences (eg /__emmett__/../rsgi/handlers.py) to read arbitrary files outside the assets directory. This vulnerability is fixed in 2.8.1.

Frequently asked questions

What is CVE-2026-39847?
Emmett is a full-stack Python web framework designed with simplicity. From 2.5.0 to before 2.8.1, the RSGI static handler for Emmett's internal assets (/__emmett__ paths) is vulnerable to path traversal attacks. An attacker can use ../ sequences (eg /__emmett__/../rsgi/handlers.py) to read arbitrary files outside the assets directory. This vulnerability is fixed in 2.8.1.
How severe is CVE-2026-39847?
CVE-2026-39847 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2026-39847 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-39847?
CVE-2026-39847 affects Emmett. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-39847?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-39847 have an EU (EUVD) identifier?
Yes. CVE-2026-39847 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19974.
When was CVE-2026-39847 published?
CVE-2026-39847 was published on 2026-04-07 and last updated on 2026-06-17.

References

Affected products (1)

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