How severe is CVE-2026-28807?

CVE-2026-28807 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 high, integrity none, and availability none.

Is CVE-2026-28807 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-28807?

CVE-2026-28807 affects Gleam-wisp Wisp. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-28807?

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-2026-28807 have an EU (EUVD) identifier?

Yes. CVE-2026-28807 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10906.

When was CVE-2026-28807 published?

CVE-2026-28807 was published on 2026-03-10 and last updated on 2026-06-17.

CVE-2026-28807

CVE-2026-28807 is a high-severity vulnerability in Gleam-wisp Wisp 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-22.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 1% (60th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-10906
Weakness: CWE-22
Affected product: Gleam-wisp Wisp
Published: 2026-03-10
Last modified: 2026-06-17

Description

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in gleam-wisp wisp allows arbitrary file read via percent-encoded path traversal. The wisp.serve_static function is vulnerable to path traversal because sanitization runs before percent-decoding. The encoded sequence %2e%2e passes through string.replace unchanged, then uri.percent_decode converts it to .., which the OS resolves as directory traversal when the file is read. An unauthenticated attacker can read any file readable by the application process in a single HTTP request, including application source code, configuration files, secrets, and system files. This issue affects wisp: from 2.1.1 before 2.2.1.

Frequently asked questions

What is CVE-2026-28807?: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in gleam-wisp wisp allows arbitrary file read via percent-encoded path traversal. The wisp.serve_static function is vulnerable to path traversal because sanitization runs before percent-decoding. The encoded sequence %2e%2e passes through string.replace unchanged, then uri.percent_decode converts it to .., which the OS resolves as directory traversal when the file is read. An unauthenticated attacker can read any file readable by the application process in a single HTTP request, including application source code, configuration files, secrets, and system files. This issue affects wisp: from 2.1.1 before 2.2.1.
How severe is CVE-2026-28807?: CVE-2026-28807 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 high, integrity none, and availability none.
Is CVE-2026-28807 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-28807?: CVE-2026-28807 affects Gleam-wisp Wisp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-28807?: 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-2026-28807 have an EU (EUVD) identifier?: Yes. CVE-2026-28807 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10906.
When was CVE-2026-28807 published?: CVE-2026-28807 was published on 2026-03-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:gleam-wisp:wisp:*:*:*:*:*:*:*:*

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