Vulnerability-Lookup

GHSA-2QVG-QR73-MQXP

Vulnerability from github – Published: 2026-08-17 13:35 – Updated: 2026-08-17 13:35

Summary

conflibot vulnerable to command injection via crafted pull request branch names under pull_request_target

Details

Impact

Versions of conflibot before 1.2.1 build git commands by string interpolation and run them through a shell. Several of the interpolated values are pull request branch names (head.ref), which are attacker-controlled: anyone can open a pull request (including from a fork) whose head branch name contains shell metacharacters such as `, $( ), ;, |, or &.

The recommended workflow runs conflibot on the pull_request_target event, where the job has access to the base repository's secrets and a write-scoped GITHUB_TOKEN. As a result, a crafted branch name causes arbitrary command execution on the runner with that write token in the environment, allowing an attacker to exfiltrate secrets and the token, push to the repository, or otherwise abuse the token's permissions. No special privileges and no maintainer interaction are required — the action runs automatically when the pull request is opened.

Affected configurations

Any workflow using wktk/conflibot at a version earlier than 1.2.1. The risk is highest under pull_request_target (the documented configuration), because that is where the write token and secrets are exposed to attacker-influenced refs.

Patches

Fixed in 1.2.1 and 2.0.0. All git invocations now use argument arrays via execFile/spawn instead of a shell, so branch names can no longer be interpreted as shell syntax, and pull requests are referenced by number through refs/pull/<n>/head rather than by branch name.

Workarounds

There is no configuration-only workaround for affected versions. Upgrade to wktk/conflibot@v2. On GitHub-hosted runners this is a drop-in upgrade; self-hosted runners additionally need Node.js 24 support and git 2.38 or later.

Resources

Fix (v2.0.0): https://github.com/wktk/conflibot/commit/0107ac6
Fix (v1.2.1): https://github.com/wktk/conflibot/commit/59e255c
Releases: https://github.com/wktk/conflibot/releases/tag/v2.0.0 and https://github.com/wktk/conflibot/releases/tag/v1.2.1

Severity

9.1 (Critical)


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

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JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "GitHub Actions",
        "name": "wktk/conflibot"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55158"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-78"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-08-17T13:35:07Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "### Impact\n\nVersions of conflibot before `1.2.1` build `git` commands by string interpolation and run them through a shell. Several of the interpolated values are pull request branch names (`head.ref`), which are attacker-controlled: anyone can open a pull request (including from a fork) whose head branch name contains shell metacharacters such as `` ` ``, `$( )`, `;`, `|`, or `\u0026`.\n\nThe recommended workflow runs conflibot on the `pull_request_target` event, where the job has access to the base repository\u0027s secrets and a write-scoped `GITHUB_TOKEN`. As a result, a crafted branch name causes arbitrary command execution on the runner with that write token in the environment, allowing an attacker to exfiltrate secrets and the token, push to the repository, or otherwise abuse the token\u0027s permissions. No special privileges and no maintainer interaction are required \u2014 the action runs automatically when the pull request is opened.\n\n### Affected configurations\n\nAny workflow using `wktk/conflibot` at a version earlier than `1.2.1`. The risk is highest under `pull_request_target` (the documented configuration), because that is where the write token and secrets are exposed to attacker-influenced refs.\n\n### Patches\n\nFixed in `1.2.1` and `2.0.0`. All `git` invocations now use argument arrays via `execFile`/`spawn` instead of a shell, so branch names can no longer be interpreted as shell syntax, and pull requests are referenced by number through `refs/pull/\u003cn\u003e/head` rather than by branch name.\n\n### Workarounds\n\nThere is no configuration-only workaround for affected versions. Upgrade to `wktk/conflibot@v2`. On GitHub-hosted runners this is a drop-in upgrade; self-hosted runners additionally need Node.js 24 support and git 2.38 or later.\n\n### Resources\n\n- Fix (v2.0.0): https://github.com/wktk/conflibot/commit/0107ac6\n- Fix (v1.2.1): https://github.com/wktk/conflibot/commit/59e255c\n- Releases: https://github.com/wktk/conflibot/releases/tag/v2.0.0 and https://github.com/wktk/conflibot/releases/tag/v1.2.1",
  "id": "GHSA-2qvg-qr73-mqxp",
  "modified": "2026-08-17T13:35:07Z",
  "published": "2026-08-17T13:35:07Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/wktk/conflibot/security/advisories/GHSA-2qvg-qr73-mqxp"
    },
    {
      "type": "WEB",
      "url": "https://github.com/wktk/conflibot/commit/0107ac6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/wktk/conflibot/commit/59e255c"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/wktk/conflibot"
    },
    {
      "type": "WEB",
      "url": "https://github.com/wktk/conflibot/releases/tag/v1.2.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/wktk/conflibot/releases/tag/v2.0.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "conflibot vulnerable to command injection via crafted pull request branch names under pull_request_target"
}

CVE-2026-55158 (GCVE-0-2026-55158)

Vulnerability from cvelistv5 – Published: 2026-09-15 14:47 – Updated: 2026-09-15 14:47

Title

Conflibot: Command injection via crafted pull request branch names under pull_request_target

Summary

Conflibot warns in advance when merging a pull request will cause conflicts in other open pull requests. Prior to 1.2.1, src/index.ts builds git checkout, git merge, and git format-patch commands by interpolating the attacker-controlled pull request head.ref value into strings passed to exec. In the documented pull_request_target configuration, an attacker can open a pull request, including from a fork, whose branch name contains shell metacharacters, and the workflow automatically interprets those characters as commands without maintainer interaction. The commands execute on a runner with base-repository secrets and a write-scoped GITHUB_TOKEN, allowing arbitrary command execution, secret or token exfiltration, unauthorized pushes, and other token abuse. The fixed implementations in src/index.ts and src/conflibot.ts use execFile or spawn argument arrays, and the v2 line also uses numeric pull-request refs rather than branch names. This issue is fixed in versions 1.2.1 and 2.0.0.

Severity

9.1 (Critical)


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

CWE

CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Assigner

GitHub_M mitre root

References

6 references

URL	Tags
https://github.com/wktk/conflibot/security/adviso…	x_refsource_CONFIRM
https://github.com/wktk/conflibot/pull/329	x_refsource_MISC
https://github.com/wktk/conflibot/commit/0107ac6a…	x_refsource_MISC
https://github.com/wktk/conflibot/commit/59e255c4…	x_refsource_MISC
https://github.com/wktk/conflibot/releases/tag/v1.2.1	x_refsource_MISC
https://github.com/wktk/conflibot/releases/tag/v2.0.0	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
wktk	conflibot	Affected: < 1.2.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "conflibot",
          "vendor": "wktk",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.2.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Conflibot warns in advance when merging a pull request will cause conflicts in other open pull requests. Prior to 1.2.1, src/index.ts builds git checkout, git merge, and git format-patch commands by interpolating the attacker-controlled pull request head.ref value into strings passed to exec. In the documented pull_request_target configuration, an attacker can open a pull request, including from a fork, whose branch name contains shell metacharacters, and the workflow automatically interprets those characters as commands without maintainer interaction. The commands execute on a runner with base-repository secrets and a write-scoped GITHUB_TOKEN, allowing arbitrary command execution, secret or token exfiltration, unauthorized pushes, and other token abuse. The fixed implementations in src/index.ts and src/conflibot.ts use execFile or spawn argument arrays, and the v2 line also uses numeric pull-request refs rather than branch names. This issue is fixed in versions 1.2.1 and 2.0.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-78",
              "description": "CWE-78: Improper Neutralization of Special Elements used in an OS Command (\u0027OS Command Injection\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-15T14:47:58.804Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/wktk/conflibot/security/advisories/GHSA-2qvg-qr73-mqxp",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/wktk/conflibot/security/advisories/GHSA-2qvg-qr73-mqxp"
        },
        {
          "name": "https://github.com/wktk/conflibot/pull/329",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/wktk/conflibot/pull/329"
        },
        {
          "name": "https://github.com/wktk/conflibot/commit/0107ac6a4575ea200d0b92287ea58f975be9505d",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/wktk/conflibot/commit/0107ac6a4575ea200d0b92287ea58f975be9505d"
        },
        {
          "name": "https://github.com/wktk/conflibot/commit/59e255c49c920fd6b67471ab9ef3bf194439a3f2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/wktk/conflibot/commit/59e255c49c920fd6b67471ab9ef3bf194439a3f2"
        },
        {
          "name": "https://github.com/wktk/conflibot/releases/tag/v1.2.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/wktk/conflibot/releases/tag/v1.2.1"
        },
        {
          "name": "https://github.com/wktk/conflibot/releases/tag/v2.0.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/wktk/conflibot/releases/tag/v2.0.0"
        }
      ],
      "source": {
        "advisory": "GHSA-2qvg-qr73-mqxp",
        "discovery": "UNKNOWN"
      },
      "title": "Conflibot: Command injection via crafted pull request branch names under pull_request_target"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-55158",
    "datePublished": "2026-09-15T14:47:58.804Z",
    "dateReserved": "2026-06-16T15:13:28.165Z",
    "dateUpdated": "2026-09-15T14:47:58.804Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.