CVE-2026-44723Public exploitNetwork attack vector

Authenticated shell execution via crafted pull request title

Published May 26, 2026 · Updated May 26, 2026

Command injection in Vowpal Wabbit's CI workflow allows remote authenticated users to execute arbitrary shell commands through a pull request title. The python_checks.yml workflow places the pull_request.title template expression inside double-quoted Bash arguments, so quote-breaking title text becomes shell source before Python starts. Any GitHub user able to open a pull request can reach all four Ubuntu runner jobs, gaining command execution as the runner account while fork pull requests receive only a read-only token and no repository secrets.

CVSS severity5.0
Medium
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Vowpal Wabbit's CI workflow allows remote authenticated users to execute arbitrary shell commands through a pull request title. The python_checks.yml workflow places the pull_request.title template expression inside double-quoted Bash arguments, so quote-breaking title text becomes shell source before Python starts. Any GitHub user able to open a pull request can reach all four Ubuntu runner jobs, gaining command execution as the runner account while fork pull requests receive only a read-only token and no repository secrets.

The record

CVE
CVE-2026-44723
Published
May 26, 2026
Updated
May 26, 2026
Vendor
VowpalWabbit
Product
Vowpal Wabbit
Classifications
CWE-78, CWE-1336, T1059.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 26, 2026CVE publishedPublication date reported by the CVE source.
  2. May 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 998e390e80a7e8192d7849b7784bc113dbd190ad

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

VowpalWabbit · Vowpal Wabbitversion=< 998e390e80a7e8192d7849b7784bc113dbd190ad

Published CVSS scores

9.9NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
5.0GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-1336Improper Neutralization of Special Elements Used in a Template Engine
T1059.004Unix Shell

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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