CVE-2026-54328

Cross-user code execution via predictable extension paths

Published Jun 23, 2026 · Updated Jun 23, 2026

Temporary-path hijacking in Earendil Inc. Pi 0.74.0 through 0.78.0 allows local users to execute extension code as another user. For temporary npm or git sources passed through --extension or -e, resource resolution trusts an existing deterministic path under os.tmpdir()/pi-extensions and the loader executes extensions found there. Exploitation requires write access to a shared temporary directory and a victim on the same Linux host to invoke a matching temporary source; macOS and Windows defaults are user-scoped.

CVSS severity7.3
High
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Temporary-path hijacking in Earendil Inc. Pi 0.74.0 through 0.78.0 allows local users to execute extension code as another user. For temporary npm or git sources passed through --extension or -e, resource resolution trusts an existing deterministic path under os.tmpdir()/pi-extensions and the loader executes extensions found there. Exploitation requires write access to a shared temporary directory and a victim on the same Linux host to invoke a matching temporary source; macOS and Windows defaults are user-scoped.

The record

CVE
CVE-2026-54328
Published
Jun 23, 2026
Updated
Jun 23, 2026
Vendor
Earendil Inc.
Product
Pi
Classifications
CWE-379, T1574
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=>= 0.74.0, < 0.78.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Earendil Inc. · Piversion=>= 0.74.0, < 0.78.1

Published CVSS scores

7.3GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-379Creation of Temporary File in Directory with Insecure Permissions
T1574Hijack Execution Flow

Public exploit references

No public exploit references are available in this record.

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo