How severe is CVE-2021-28161?

CVE-2021-28161 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-28161?

CVE-2021-28161 affects the following packages: @theia/console (npm). Ecosystems affected: npm.

How do I fix CVE-2021-28161?

Update @theia/console to 1.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-28161 is resolved across your whole dependency graph.

How do I detect CVE-2021-28161 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @theia/console. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2021-28161 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2021-28161?

O3 pinpoints whether CVE-2021-28161 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2021-28161 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2021-28161, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

When was CVE-2021-28161 published, and has it been updated?

CVE-2021-28161 was published on March 12, 2021 and was last updated on August 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

MEDIUM severity

CVE-2021-28161

MEDIUM

CVE-2021-28161 is a medium-severity (CVSS 6.1) vulnerability in @theia/console. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2021-28161 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Improper Neutralization of Input in Theia console

Also known asGHSA-cwg9-c9cr-p5fq

Published

Mar 12, 2021

Updated

Aug 7, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Aug 7, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

5other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@theia/consolenpm

12Kdownloads / week

Description

In Eclipse Theia versions up to and including 1.8.0, in the debug console there is no HTML escaping, so arbitrary Javascript code can be injected.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@theia/console`	all versions	1.8.1

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

In Eclipse Theia versions up to and including 1.8.0, in the debug consol…

github.comNVDMar 2021

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @theia/console. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @theia/console to 1.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-28161 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 pinpoints whether CVE-2021-28161 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2021-28161. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

In Eclipse Theia versions up to and including 1.8.0, in the debug console there is no HTML escaping, so arbitrary Javascript code can be injected.

O3 Security · Impact-Aware SCA

Is CVE-2021-28161 in your dependencies?

O3 detects CVE-2021-28161 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works