Vulnerability · Published Oct 15, 2026 · Assigned by GitHub_M

CVE-2026-104266tinytag: Infinite loop when parsing certain M4A files containing invalid atoms

Medium 6.5

In plain English

A medium-severity infinite loop in tinytag from tinytag. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.3%top 73.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

tinytag is a Python library for reading audio file metadata. From 2.0.0 until 2.3.0, an M4A file containing a sub-atom with a size of zero inside a ---- atom can cause the metadata parser to stop advancing through the input. The custom-field atom traversal repeatedly processes the malformed location, causing an infinite loop and denying service to a program that reads the crafted file. This issue is fixed in version 2.3.0.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:14	python-tinytag	2.3.0-1	DEBIAN-CVE-2026-104266
PyPI	tinytag	2.3.0	GHSA-24cc-9352-h2pg
Ubuntu:26.10	python-tinytag	no fix listed	UBUNTU-CVE-2026-104266

Affected products (as reported)

Vendor	Product	Versions
tinytag	tinytag	>= 2.0.0, < 2.3.0

Weakness: CWE-835 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References

https://github.com/tinytag/tinytag/security/advisories/GHSA-24cc-9352-h2pg x_refsource_CONFIRM
https://github.com/tinytag/tinytag/pull/326 x_refsource_MISC
https://github.com/tinytag/tinytag/commit/9ada221ba44990cb02cd9002d992186e037b515e x_refsource_MISC
https://github.com/tinytag/tinytag/releases/tag/2.3.0 x_refsource_MISC