CVE-2026-55158VulnerabilityPublished 17 Aug 2026

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

Affects wktk/conflibotSource GCVE Database

Authoritative record:CVE-2026-55158· Critical 9.1

Not known to be exploited · CVSS 9.1 Critical : upgrade to 1.2.1 as a priority.

Data as of 26 Oct 2026, 09:16 UTC

CVSS 3.1 base score

9.1Critical

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.8% chance of exploitation in 30 days – higher than 56% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.2.1

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade wktk/conflibot to 1.2.1.

Affected software

Product	Affected	Fixed in
GitHubwktk/conflibot	Affected <1.2.1	Fixed in 1.2.1

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Description

### 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 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

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #9OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
Architecture and Design
If at all possible, use library calls rather than external processes to recreate the desired functionality.
Architecture and Design · Operation · Sandbox or Jail
Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.
Architecture and Design · Attack Surface Reduction
For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
OWASP Cheat Sheets
Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
OS Command Injection Defense (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.5 (opens in a new tab)
V5.3.8 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
Command Line Execution through SQL Injection (opens in a new tab)
Command Delimiters (opens in a new tab)
Exploiting Multiple Input Interpretation Layers (opens in a new tab)
Argument Injection (opens in a new tab)
OS Command Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

WeaknessesCWE-78

Technical details

References

Community reviews

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