CVE-2026-54326 (GCVE-0-2026-54326)

Vulnerability from cvelistv5 – Published: 2026-06-23 19:26 – Updated: 2026-06-24 13:09

Title

Pi: Potential XSS in HTML session exports via Markdown URL sanitization bypass

Summary

Pi is a minimal terminal coding harness. From 0.74.0 until 0.78.1, Pi HTML exports render session Markdown into a static HTML file. It did not consistently reject unsafe Markdown link and image URL schemes. In versions with scheme filtering, C0 control characters in the URL scheme could bypass the check because browsers normalize those characters before navigation. This vulnerability is fixed in 0.78.1.

Severity

2.5 (Low)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Assigner

GitHub_M

References

3 references

URL	Tags
https://github.com/earendil-works/pi/security/adv…	x_refsource_CONFIRM
https://github.com/earendil-works/pi/commit/6cb23…	x_refsource_MISC
https://github.com/earendil-works/pi/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
earendil-works	pi	Affected: >= 0.74.0, < 0.78.1

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GHSA-7V5M-PR3Q-6453

Vulnerability from github – Published: 2026-06-16 23:43 – Updated: 2026-06-16 23:43

Summary

Pi Agent: Potential XSS in HTML session exports via Markdown URL sanitization bypass

Details

Potential XSS in HTML session exports via Markdown URL handling

Pi HTML exports render session Markdown into a static HTML file. Affected versions did not consistently reject unsafe Markdown link and image URL schemes. In versions with scheme filtering, C0 control characters in the URL scheme could bypass the check because browsers normalize those characters before navigation.

Impact

The realistic attack path is indirect. An attacker would need to get suitable Markdown into a session, for example through prompt injection that causes the model to include an unsafe link, or through other untrusted session content. The user would then need to export the session as HTML, open or share that file, and click the link.

If triggered, script runs in the exported document, not in pi or the user's shell. The main risk is limited disclosure of data embedded in that exported session file.

Affected versions

Affected: @mariozechner/pi-coding-agent >= 0.27.5, <= 0.73.1
Affected: @earendil-works/pi-coding-agent >= 0.74.0, < 0.78.1
Patched: @earendil-works/pi-coding-agent 0.78.1

The old @mariozechner/pi-coding-agent package scope has no patched release. It was renamed to @earendil-works/pi-coding-agent; users of the old scope should migrate to the new package and upgrade to version 0.78.1 or later.

Resolution

Version 0.78.1 sanitizes Markdown link and image URLs with an allow-list after stripping C0 control characters.

Recommendations

Upgrade @earendil-works/pi-coding-agent to version 0.78.1 or later. Regenerate shared HTML exports after upgrading if the underlying sessions contained untrusted content.

Timeline

2026-05-29: Report received through GitHub Security Advisories
2026-06-02: Fix committed
2026-06-04: Fixed version 0.78.1 released
2026-06-08: Advisory prepared for publication

Credits

Reported by Paul Urian and Cosmin Alexa of CrowdStrike.