Vulnerability · Published Jul 8, 2026 · Assigned by VulnCheck

CVE-2026-58654Grav - Arbitrary File Upload via Avatar Endpoint

Medium 4.3

In plain English

A medium-severity unrestricted file upload in Grav from Grav. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities).

Severity (CVSS 3.1)4.3Medium

Exploit odds (30 days)0.4%top 61.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

The Grav API plugin (getgrav/grav-plugin-api) 1.0.0 contains an unrestricted file upload vulnerability in the avatar upload endpoint (/api/v1/users/user/avatar). The endpoint validates only the client-declared MIME type (getClientMediaType) beginning with 'image/' and does not inspect the actual file content or restrict the resulting extension, allowing an authenticated user to store arbitrary content — including PHP code, SVG with embedded JavaScript, and polyglot payloads — under user/accounts/avatars/ with predictable filenames. Direct HTTP access to the stored files is blocked by .htaccess (returns 403), but the files persist on disk and could lead to remote code execution or stored XSS in the presence of a path traversal flaw or server misconfiguration. Fixed in 1.0.1.

Affected products (as reported)

Vendor	Product	Versions
Grav	Grav	0 – before 1.0.1

Weakness: CWE-434 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

References

GitHub Security Advisory (GHSA-xc64-vh46-vph6) vendor-advisory
VulnCheck Advisory: Grav - Arbitrary File Upload via Avatar Endpoint third-party-advisory