---
id: CVE-2026-9147
title: >-
  uproot dynamically generates Python class source code from ROOT TStreamerInfo
  records in a file and compiles it at runtime
summary: >-
  uproot dynamically generates Python class source code from ROOT TStreamerInfo
  records in a file and compiles it at runtime. Some file-controlled streamer
  metadata fields (for example, streamer element names) are interpolated into
  the gen…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-94
published: '2026-07-18'
updated: '2026-07-18'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-9147'
references:
  - url: 'https://github.com/scikit-hep/uproot5'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/scikit-hep/uproot5/commit/c045c2824295d907d2e705f31110c742928e50e7
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/scikit-hep/uproot5/security/advisories/GHSA-6946-mq52-g438
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/uproot-and-before-code-injection-via-tstreamerinfo-metadata
    label: disclosure@vulncheck.com
tags:
  - nvd
  - exploit-available
ingestedAt: '2026-07-19T03:27:58.209Z'
epss: 0.00224
epssPercentile: 0.13256
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/SaiTeja-Erukude/CVE-2026-9147-uproot-rce'
  checkedAt: '2026-09-23T07:15:19.359Z'
exploitAvailable: true
---

## Overview

uproot dynamically generates Python class source code from ROOT TStreamerInfo records in a file and compiles it at runtime. Some file-controlled streamer metadata fields (for example, streamer element names) are interpolated into the generated Python source without safe quoting via repr() or the !r format specifier. An attacker who can supply a crafted ROOT file can place Python expression-breaking content into a streamer metadata field. When uproot generates and invokes the corresponding reader method, the injected Python expression is evaluated in the context of the process opening the file, resulting in arbitrary Python code execution in applications that open or process attacker-controlled ROOT files with affected uproot code paths.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.