CVE-2026-79661 — Ech0
CVE-2026-79661 is a CWE-770 vulnerability in github.com/lin-snow/Ech0. A fix is available for github.com/lin-snow/Ech0 — see the affected versions and patch details below.
Ech0 before 4.7.3 Unauthenticated fav_count Modification
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-79661.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
github.com/lin-snow/Ech0Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Ech0 through 4.5.6 registers the PUT /api/echo/like/:id endpoint on the public router group without authentication or rate limiting. Unauthenticated attackers can increment the fav_count counter of any echo (including private echoes) by supplying its UUID, which can be harvested from the public GET /api/echo/page feed. Repeated requests are accepted without deduplication, each triggering a database write and a four-key cache invalidation, allowing attackers to inflate popularity metrics and amplify load on the database and cache. Fixed in 4.7.3.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/lin-snow/Ech0 | all versions | 1.4.8-0.20260503035905-cecc2c19b590go get github.com/lin-snow/Ech0@v1.4.8-0.20260503035905-cecc2c19b590 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/lin-snow/Ech0, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/lin-snow/Ech0 to 1.4.8-0.20260503035905-cecc2c19b590 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-79661 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-79661 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-79661. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-79661 in your dependencies?
O3 Security finds CVE-2026-79661 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.