CVE-2026-35583 Emissary has a Path Traversal via Blacklist Bypass in Configuration API

Medium 5.3 Published 7 Apr 2026 Updated 9 Apr 2026

Attackers can bypass blacklist validation in the configuration API to read arbitrary files outside the intended directory via path traversal.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-35583?

CVE-2026-35583 is a medium-severity path traversal vulnerability in NationalSecurityAgency emissary, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Emissary is a P2P based data-driven workflow engine. Prior to 8.39.0, the configuration API endpoint (/api/configuration/{name}) validated configuration names using a blacklist approach that checked for \, /, .., and trailing .. This could potentially be bypassed using URL-encoded variants, double-encoding, or Unicode normalization to achieve path traversal and read configuration files outside the intended directory. This vulnerability is fixed in 8.39.0.

Weakness: CWE-22

Which versions are affected by CVE-2026-35583?

2 open source packages ship an affected version, including gov.nsa.emissary:emissary. It affects 1 product.

Package	Affected	Fixed in
`gov.nsa.emissary:emissary` Maven	All versions	`8.39.0`
`gov.nsa.emissary:emissary` Maven	All versions	`8.39.0`

Products include Nsa Emissary.

How do I fix CVE-2026-35583?

Upgrade gov.nsa.emissary:emissary to 8.39.0 or later.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-35583 being exploited?

There is no known exploitation of CVE-2026-35583 in the wild and no public exploit code.

Sources

Also known as GHSA-hxf2-gm22-7vcm.