CVE-2026-62866 Dasel: Selector lexer panics on trailing whitespace in `parseCurRune`
A remote attacker can cause a denial of service by providing a selector with trailing whitespace, triggering a panic in the Dasel library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-62866?
CVE-2026-62866 is a medium-severity denial of service vulnerability in TomWright dasel, published on 21 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Dasel is a command-line tool and library for querying, modifying, and transforming data structures. From 3.0.0 until 3.11.2, selector/lexer/tokenize.go parseCurRune advances the input index across trailing whitespace and then reads the source at the exhausted index without an end-of-input check. A selector ending in whitespace, including input passed through lexer.NewTokenizer(...).Tokenize() or dasel.Query, can therefore cause an index-out-of-range panic and terminate the process. This issue is fixed in version 3.11.2.
Weakness: CWE-129
Which versions are affected by CVE-2026-62866?
5 open source packages ship an affected version, including github.com/tomwright/dasel/v3, github.com/tomwright/dasel and github.com/tomwright/dasel/v2.
| Package | Affected | Fixed in |
|---|---|---|
github.com/tomwright/dasel/v3 Go | From 3.0.0 | 3.11.2 |
github.com/tomwright/dasel/v3 Go | From 3.0.0 | 3.11.2 |
github.com/tomwright/dasel/v3 Go | From 3.0.0 | 3.11.2 |
github.com/tomwright/dasel Go | All versions | None |
github.com/tomwright/dasel/v2 Go | All versions | None |
How do I fix CVE-2026-62866?
Upgrade github.com/tomwright/dasel/v3 to 3.11.2 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-62866 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-62866 exists.
Sources
Also known as DEBIAN-CVE-2026-62866, GHSA-65gg-g7rw-6cpc, GO-2026-6548, UBUNTU-CVE-2026-62866.