GHSA-3v85-fqvh-7rxf: github.com/lin-snow/Ech0 (CVE-2026-79663)

Ech0's RSS feed renders unescaped tag names and raw-HTML markdown, stored XSS against subscribers

CVSS 4.8 MediumEPSS 0.0025 · 16th percentile

Published by the GitHub Advisory Database at 7 May 2026, 21:18 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

Package	Ecosystem	Affected	Fixed in
github.com/lin-snow/Ech0	Go	<1.4.8-0.20260503035519-fd320fe3e902	1.4.8-0.20260503035519-fd320fe3e902

Identifiers

GHSA-3v85-fqvh-7rxf · CVE-2026-79663 · GO-2026-5100

Weakness (CWE)

CWE-79 · CWE-116

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Ech0 (Go module github.com/lin-snow/Ech0) versions up to 1.4.8-0.20260503035519-fd320fe3e902 are affected. The public RSS feed renders tag names and raw HTML in Markdown without escaping, so an admin-created echo can inject script that runs in the reader of any subscriber whose RSS client renders HTML. Upgrade to 1.4.8-0.20260503035519-fd320fe3e902 or later, which contains the fix.

Written 6 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
4.8	Medium	4.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N	CNA (VulnCheck)

CISA KEV Not listed.
EPSS 0.0025, the 16th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:48 UTC First seen by agentprime
31 Oct 2026, 14:48 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.