CVE-2026-87910 tarfile hardlink fallback ignores custom extraction filter rejection via None
Attackers can bypass extraction filters in Python's tarfile module to write files to arbitrary locations, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-87910?
CVE-2026-87910 is a medium-severity path traversal vulnerability in CPython, published on 11 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
When tarfile extracts a link on a system that doesn't support links, it falls back to extracting a member from the archive. In this case, the filter function is run twice: once for the extracted member, and once with name set to the location of the link. For one of the calls, the return value was ignored. Instead, the member should be skipped if either call returns None.
Which versions are affected by CVE-2026-87910?
3 open source packages ship an affected version, including libpython, python and python-min.
| Package | Affected | Fixed in |
|---|---|---|
libpython Bitnami | All versions | 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.9 |
python Bitnami | All versions | 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.9 |
python-min Bitnami | All versions | 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.9 |
Linux distribution packages (30)
python3.10 Red Hat:hummingbird:1 | All versions | 0:3.10.21-1.2.hum1 |
python3.10-debug Red Hat:hummingbird:1 | All versions | 0:3.10.21-1.2.hum1 |
python3.10-devel Red Hat:hummingbird:1 | All versions | 0:3.10.21-1.2.hum1 |
python3.10-idle Red Hat:hummingbird:1 | All versions | 0:3.10.21-1.2.hum1 |
python3.10-libs Red Hat:hummingbird:1 | All versions | 0:3.10.21-1.2.hum1 |
python3.10-test Red Hat:hummingbird:1 | All versions | 0:3.10.21-1.2.hum1 |
python3.10-tkinter Red Hat:hummingbird:1 | All versions | 0:3.10.21-1.2.hum1 |
python3.11 Red Hat:hummingbird:1 | All versions | 0:3.11.16-1.3.hum1 |
python3.11-debug Red Hat:hummingbird:1 | All versions | 0:3.11.16-1.3.hum1 |
python3.11-devel Red Hat:hummingbird:1 | All versions | 0:3.11.16-1.3.hum1 |
python3.11-idle Red Hat:hummingbird:1 | All versions | 0:3.11.16-1.3.hum1 |
python3.11-libs Red Hat:hummingbird:1 | All versions | 0:3.11.16-1.3.hum1 |
python3.11-test Red Hat:hummingbird:1 | All versions | 0:3.11.16-1.3.hum1 |
python3.11-tkinter Red Hat:hummingbird:1 | All versions | 0:3.11.16-1.3.hum1 |
python3.12 Red Hat:hummingbird:1 | All versions | 0:3.12.14-1.2.hum1 |
python3.12-debug Red Hat:hummingbird:1 | All versions | 0:3.12.14-1.2.hum1 |
python3.12-devel Red Hat:hummingbird:1 | All versions | 0:3.12.14-1.2.hum1 |
python3.12-idle Red Hat:hummingbird:1 | All versions | 0:3.12.14-1.2.hum1 |
python3.12-libs Red Hat:hummingbird:1 | All versions | 0:3.12.14-1.2.hum1 |
python3.12-test Red Hat:hummingbird:1 | All versions | 0:3.12.14-1.2.hum1 |
python3.12-tkinter Red Hat:hummingbird:1 | All versions | 0:3.12.14-1.2.hum1 |
python3.13 Red Hat:hummingbird:1 | All versions | 0:3.13.15-1.2.hum1 |
python3.13-debug Red Hat:hummingbird:1 | All versions | 0:3.13.15-1.2.hum1 |
python3.13-devel Red Hat:hummingbird:1 | All versions | 0:3.13.15-1.2.hum1 |
python3.13-freethreading Red Hat:hummingbird:1 | All versions | 0:3.13.15-1.2.hum1 |
python3.13-freethreading-debug Red Hat:hummingbird:1 | All versions | 0:3.13.15-1.2.hum1 |
python3.13-idle Red Hat:hummingbird:1 | All versions | 0:3.13.15-1.2.hum1 |
python3.13-libs Red Hat:hummingbird:1 | All versions | 0:3.13.15-1.2.hum1 |
python3.13-test Red Hat:hummingbird:1 | All versions | 0:3.13.15-1.2.hum1 |
python3.13-tkinter Red Hat:hummingbird:1 | All versions | 0:3.13.15-1.2.hum1 |
How do I fix CVE-2026-87910?
Upgrade libpython to a fixed version for your release line: 3.10.22, 3.11.17, 3.12.15 or 3.13.16.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-87910 being exploited?
There is no known exploitation of CVE-2026-87910 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-87910, AZL-103383, BELL-CVE-2026-87910, BIT-libpython-2026-87910, BIT-python-2026-87910, BIT-python-min-2026-87910 and 13 more.