CPython is a ubiquitous runtime; tarfile is widely used in apps, CI, and tooling. This flaw can alter or expose files outside extract dirs, risking data loss, tampering, or supply-chain impact across organizations.
CVE-2026-82049
Tarfile hardlink->symlink trick lets crafted tars expose or modify files outside extraction dir.
Is CVE-2026-82049 being exploited?
Not confirmed. CVE-2026-82049 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.18% probability of exploitation in the next 30 days.
How severe is CVE-2026-82049?
CVE-2026-82049 is rated High with a CVSS score of 8.4. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-82049?
Yes. A fix has been recorded for CVE-2026-82049. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-82049 affect?
CVE-2026-82049 affects CPython <= 3.13 (tarfile module), Applications/libraries using Python tarfile.extract* or filters, Developer/build systems and CI that unpack untrusted tarballs. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-82049?
Apply the CPython security patch immediately; avoid extracting untrusted tarballs and sanitize archives.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Extracting a crafted tar can modify permissions/mtime or expose contents of files outside the target dir, enabling file tampering or data disclosure.
Immediate action required
- affected< 3.14.0b1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.