Dasel: Index-out-of-range panic in dasel selector lexer on trailing backslash in quoted string

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-46377: 0.19% estimated exploitation activity in the next 30 days; percentile 8.55 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary dasel's selector lexer panics with an index-out-of-range error when tokenizing a quoted string that ends with a trailing backslash (e.g., "\ or '\). A 2-byte input causes an immediate process crash via Go runtime panic. I confirmed the issue on v3.3.1 (fba653c7f248aff10f2b89fca93929b64707dfc8) and on master commit 0dd6132e0c58edbd9b1a5f7ffd00dfab1e6085ad. I also verified the same code path is present in v3.0.0 (648f83baf070d9e00db8ff312febef857ec090a3). No fix is available yet. Details The bug is in the escape sequence handler within (Tokenizer).parseCurRune in selector/lexer/tokenize.go#L191-L194: When a backslash is the last character inside quotes, pos++ increments the position past the end of the input. The subsequent p.src[pos] attempts to read past the end of the slice, which Go turns into a runtime panic: runtime error: index out of range [2] with length 2. Notably, the same function already handles unterminated quoted strings by returning UnexpectedEOFError, but the…

Published by the source

19 May 2026, 20:08 UTC

Last modified by the source

19 May 2026, 20:08 UTC

Source last checked

26 Oct 2026, 15:22 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-m5j3-4634-c2vq

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# Patch Next advisory brief: CVE-2026-46377

Advisory: Dasel: Index-out-of-range panic in dasel selector lexer on trailing backslash in quoted string
IDs: CVE-2026-46377, GHSA-m5j3-4634-c2vq
Record: https://patchnext.com/advisories/cve-2026-46377 (revision 1, source checked 26 Oct 2026, 15:22 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/tomwright/dasel/v3: affected >= 3.0.0, <= 3.10.0

## Suggested inspection (read-only)
- Go github.com/tomwright/dasel/v3: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/tomwright/dasel/v3.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-m5j3-4634-c2vq (GitHub-reviewed advisory GHSA-m5j3-4634-c2vq lists affected ranges: Go github.com/tomwright/dasel/v3 >=3.0.0 <=3.10.0)

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