How severe is CVE-2026-58266?

CVE-2026-58266 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-58266?

CVE-2026-58266 affects the following packages: aqt (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-58266?

Update aqt to 25.9.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-58266 is resolved across your whole dependency graph.

How do I detect CVE-2026-58266 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aqt, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-58266 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2026-58266 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-58266 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-58266?

CVE-2026-58266 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 12th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-58266?

CVE-2026-58266 is classified as CWE-346 (CWE-346). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-58266 published, and has it been updated?

CVE-2026-58266 was published on July 7, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

MEDIUM severity

CVE-2026-58266 — aqt

MEDIUMFix: ankitects/anki@b2b68d8

CVE-2026-58266 is a medium-severity (CVSS 6.5) CWE-346 vulnerability in aqt. A fix is available for aqt — see the affected versions and patch details below.

Anki: User scripts in iframes have access to the internal Anki API

Also known asGHSA-cw6h-ffmh-x6vh

Published

Jul 7, 2026

Updated

Oct 21, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 24, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-58266.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs12th percentile — riskier than 12% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-58266 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 395,249 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐍aqt

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

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

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`aqt`	all versions	25.9.4`pip install --upgrade 'aqt==25.9.4'`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aqt, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update aqt to 25.9.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-58266 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Frequently Asked Questions

## 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 | | ---------