CVE-2026-28407 malcontent's nested archive extraction failure can drop content from scan inputs
Attackers can evade detection by hiding malicious content in nested archives that fail to extract, as the tool previously discarded them instead of scanning.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-28407?
CVE-2026-28407 is a medium-severity vulnerability in chainguard-dev malcontent, published on 27 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
malcontent is software for discovering supply-chain compromises through context, differential analysis, and YARA. Prior to version 1.21.0, malcontent would remove nested archives which failed to extract which could potentially leave malicious content. A better approach is to preserve these archives so that malcontent can attempt a best-effort scan of the archive bytes. Version 1.21.0 fixes the issue.
Weakness: CWE-703
Which versions are affected by CVE-2026-28407?
3 open source packages ship an affected version, including github.com/chainguard-dev/malcontent. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/chainguard-dev/malcontent Go | All versions | 1.21.0 |
github.com/chainguard-dev/malcontent Go | All versions | 1.21.0 |
github.com/chainguard-dev/malcontent Go | All versions | 1.21.0 |
Products include Chainguard Malcontent.
How do I fix CVE-2026-28407?
Upgrade github.com/chainguard-dev/malcontent to 1.21.0 or later.
Is CVE-2026-28407 being exploited?
There is no known exploitation of CVE-2026-28407 in the wild and no public exploit code.
Other vulnerabilities in chainguard-dev malcontent
Sources
Also known as GHSA-945p-3jhm-6rcp, GO-2026-4577.