CVE-2026-58266

Anki is a program for creating and reviewing flashcards. Prior to 25.09.4, Anki's webview-based pages communicate with the Rust backend using an internal localhost API, and user scripts included via iframes in the editor can access this API despite protections intended to block reviewer and editor scripts. A malicious imported card package with an embedded iframe can use exposed API methods such as getImageForOcclusion to read arbitrary files accessible to the Anki process and exfiltrate them over the network. This issue is fixed in version 25.09.4.

Anki is a program for creating and reviewing flashcards. Prior to 25.09.4, Anki's webview-based pages communicate with the Rust backend using an internal localhost API, and user scripts included via iframes in the editor can access this API despite protections intended to block reviewer and editor scripts. A malicious imported card package with an embedded iframe can use exposed API methods such as getImageForOcclusion to read arbitrary files accessible to the Anki process and exfiltrate them over the network. This issue is fixed in version 25.09.4.

Summary

Anki's webview-based pages communicate with the Rust backend using an internal localhost API. Anki implements measures to prevent user scripts run in the reviewer/editor from accessing this API (https://github.com/ankitects/anki/pull/3925) but it inadvertently allows access to scripts included via iframes in the editor. While overall only a limited set of API methods are exposed, some such as getImageForOcclusion can read arbitrary files.

CWE: CWE-22 (Path Traversal) Reporter: Bankde (Eakasit)

Affected Products

| Ecosystem | Package | Affected Versions | | --------- | ------- | ----------------- | | PyPI | aqt | <= 25.09.3 |

Impact

Any desktop Anki user (Windows, macOS, Linux) who imports an untrusted .apkg and views card with an embedded iframe is vulnerable. No special configuration is required. The attacker can read any file accessible to the Anki process and exfiltrate its contents over the network.

Patches

A patch is available in 25.09.4

Workarounds

• Do not import .apkg files from untrusted sources.
• Inspect .apkg contents (it's a ZIP) for .html/.svg files with <script> tags before importing.
• Block unexpected outbound network requests from the Anki process at the firewall level.

References

• Vulnerability report: Anki arbitrary file read vulnerability (with exfiltration) — Bankde (Eakasit)
• Affected source: qt/aqt/mediasrv.py::_handle_local_file_request
• Related prior CVEs: CVE-2024-29073, CVE-2024-32484, CVE-2025-62185, CVE-2025-62187

Anki is a program for creating and reviewing flashcards. Prior to 25.09.4, Anki's webview-based pages communicate with the Rust backend using an internal localhost API, and user scripts included via iframes in the editor can access this API despite protections intended to block reviewer and editor scripts. A malicious imported card package with an embedded iframe can use exposed API methods such as getImageForOcclusion to read arbitrary files accessible to the Anki process and exfiltrate them over the network. This issue is fixed in version 25.09.4.

Anki is a program for creating and reviewing flashcards. Prior to 25.09.4, Anki's webview-based pages communicate with the Rust backend using an internal localhost API, and user scripts included via iframes in the editor can access this API despite protections intended to block reviewer and editor scripts. A malicious imported card package with an embedded iframe can use exposed API methods such as getImageForOcclusion to read arbitrary files accessible to the Anki process and exfiltrate them over the network. This issue is fixed in version 25.09.4.

Anki is a program for creating and reviewing flashcards. Prior to 25.09.4, Anki's webview-based pages communicate with the Rust backend using an internal localhost API, and user scripts included via iframes in the editor can access this API despite protections intended to block reviewer and editor scripts. A malicious imported card package with an embedded iframe can use exposed API methods such as getImageForOcclusion to read arbitrary files accessible to the Anki process and exfiltrate them over the network. This issue is fixed in version 25.09.4.

Summary

Anki's webview-based pages communicate with the Rust backend using an internal localhost API. Anki implements measures to prevent user scripts run in the reviewer/editor from accessing this API (https://github.com/ankitects/anki/pull/3925) but it inadvertently allows access to scripts included via iframes in the editor. While overall only a limited set of API methods are exposed, some such as getImageForOcclusion can read arbitrary files.

CWE: CWE-22 (Path Traversal) Reporter: Bankde (Eakasit)

Affected Products

| Ecosystem | Package | Affected Versions | | --------- | ------- | ----------------- | | PyPI | aqt | <= 25.09.3 |

Impact

Any desktop Anki user (Windows, macOS, Linux) who imports an untrusted .apkg and views card with an embedded iframe is vulnerable. No special configuration is required. The attacker can read any file accessible to the Anki process and exfiltrate its contents over the network.

Patches

A patch is available in 25.09.4

Workarounds

• Do not import .apkg files from untrusted sources.
• Inspect .apkg contents (it's a ZIP) for .html/.svg files with <script> tags before importing.
• Block unexpected outbound network requests from the Anki process at the firewall level.

References

• Vulnerability report: Anki arbitrary file read vulnerability (with exfiltration) — Bankde (Eakasit)
• Affected source: qt/aqt/mediasrv.py::_handle_local_file_request
• Related prior CVEs: CVE-2024-29073, CVE-2024-32484, CVE-2025-62185, CVE-2025-62187

Anki is a program for creating and reviewing flashcards. Prior to 25.09.4, Anki's webview-based pages communicate with the Rust backend using an internal localhost API, and user scripts included via iframes in the editor can access this API despite protections intended to block reviewer and editor scripts. A malicious imported card package with an embedded iframe can use exposed API methods such as getImageForOcclusion to read arbitrary files accessible to the Anki process and exfiltrate them over the network. This issue is fixed in version 25.09.4.