Snowy 3.6.5 Hard-coded Download Signature Key Allows Unauthenticated File Download

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

Snowy 3.6.5 contains a hard-coded HMAC key vulnerability that allows unauthenticated attackers to forge download signatures for the /dev/file/download endpoint by using the published FILE_DOWNLOAD_SIGN_SECRET constant. Attackers can compute HMAC-SHA256 signatures of guessed file ids offline to download stored files such as avatars, editor images and attachments.

Source published

13 Oct 2026 18:50:03 UTC

Source modified

13 Oct 2026 19:23:28 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 4.0 · 6.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS 3.1 · 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N