Risk Scores
CVSS v3.1
9.100000381469727
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Debian | python3.9 |
Timeline
- Apr 16, 2026 CVE Published
=========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2026.3780 python3.9 regression and security update 16 April 2026 =========================================================================== AUSCERT Security Bulletin Summary --------------------------------- Product: python3.9 Publisher: Debian Operating System: Debian GNU/Linux Resolution: Patch/Upgrade CVE Names: CVE-2026-6100 CVE-2025-15367 CVE-2025-15366 Original Bulletin: https://lists.debian.org/debian-lts-announce/2026/04/msg00012.html Comment: CVSS (Max): 9.1 CVE-2026-6100 (CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N) CVSS Source: Python Software Foundation Calculator: https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N EPSS (Max): 0.1% (23rd) CVE-2025-15367 2026-04-15 - --------------------------BEGIN INCLUDED TEXT-------------------- - ------------------------------------------------------------------------- Debian LTS Advisory DLA-4532-1 debian-lts@lists.debian.org https://www.debian.org/lts/security/ Arnaud Rebillout April 15, 2026 https://wiki.debian.org/LTS - ------------------------------------------------------------------------- Package : python3.9 Version : 3.9.2-1+deb11u6 CVE ID : CVE-2025-15366 CVE-2025-15367 CVE-2026-6100 Debian Bug : It was found that the patches for CVE-2025-15366 and CVE-2025-15367 break backward compatibility, and upstream decided not to backport those patches to older Python releases. Therefore those 2 patches, applied in the previous version (python3.9 3.9.2-1+deb11u5), have been reverted. Additionally, the following CVE have been fixed: CVE-2026-6100 Use-after-free (UAF) was possible in the `lzma.LZMADecompressor` and `bz2.BZ2Decompressor` when a memory allocation fails with a `MemoryError` and the decompression instance is re-used. This scenario can be triggered if the process is under memory pressure. The vulnerability is only present if the program re-uses decompressor instances across multiple decompression calls even after a `MemoryError` is raised during decompression. Using the helper functions to one-shot decompress data such as `lzma.decompress()` and `bz2.decompress()` are not affected as a new decompressor instance is used per call. If the decompressor instance is not re-used after an error condition, this usage is similarly not vulnerable. For Debian 11 bullseye, these problems have been fixed in version 3.9.2-1+deb11u6. We recommend that you upgrade your python3.9 packages. For the detailed security status of python3.9 please refer to its security tracker page at: https://security-tracker.debian.org/tracker/python3.9 Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: https://wiki.debian.org/LTS - --------------------------END INCLUDED TEXT---------------------- You have received this e-mail bulletin as a result of your organisation's registration with AUSCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AUSCERT's members. As AUSCERT did not write the document quoted above, AUSCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AUSCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://portal.auscert.org.au/bulletins/ =========================================================================== AUSCERT The University of Queensland, Brisbane QLD 4072 Australia e: auscert@auscert.org.au t: +61 (0)7 3365 4417 Allies in Cyber Security ===========================================================================
| Vendor | Product | Versions |
|---|---|---|
| Debian | python3.9 |