CVE-2026-6100
Use-after-free in lzma.LZMADecompressor, bz2.BZ2Decompressor, and gzip.GzipFile after re-use under memory pressure
Description
Use-after-free (UAF) was possible in the `lzma.LZMADecompressor`, `bz2.BZ2Decompressor`, and `gzip.GzipFile` 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 fix cleans up the dangling pointer in this specific error condition. 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()`, `bz2.decompress()`, `gzip.decompress()`, and `zlib.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.
INFO
Published Date :
April 13, 2026, 6:16 p.m.
Last Modified :
June 30, 2026, 3:21 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-6100
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | ||||
| CVSS 4.0 | CRITICAL | 28c92f92-d60d-412d-b760-e73465c3df22 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update the affected software.
- Avoid re-using decompressor instances after MemoryError.
- Use helper functions for single decompression calls.
Public PoC/Exploit Available at Github
CVE-2026-6100 has a 3 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-6100.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-6100 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-6100
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Dockerfile Shell
Dockerized Python automation tool that converts Grype vulnerability scan results into Excel reports.
Dockerfile Python
Hardened Docker infrastructure for an LLM based swedish language tutor
Python JavaScript HTML Go Template CSS
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-6100 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-6100 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Jun. 30, 2026
Action Type Old Value New Value Added Affected [{'cpes': ['cpe:/a:redhat:rhosemc:1.0::el8'], 'vendor': 'Red Hat', 'product': 'Middleware Containers for OpenShift', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux_eus:10.0'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v. 10.0)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10.1', 'cpe:/o:redhat:enterprise_linux:10.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 10)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.4::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream AUS (v.8.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus_long_life:8.4::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream AUS (v.8.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:8.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream E4S (v.8.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_tus:8.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream TUS (v.8.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:8.8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream E4S (v.8.8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_tus:8.8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream TUS (v.8.8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:9.0::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream E4S (v.9.0)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:9.2::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream E4S (v.9.2)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.4::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v.9.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v.9.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 9)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux_eus:10.0'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS EUS (v. 10.0)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10.1', 'cpe:/o:redhat:enterprise_linux:10.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS (v. 10)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:8::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS (v. 8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:rhel_aus:8.4::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS AUS (v.8.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:rhel_eus_long_life:8.4::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:rhel_aus:8.6::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS AUS (v.8.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:rhel_e4s:8.6::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS E4S (v.8.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:rhel_tus:8.6::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS TUS (v.8.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:rhel_e4s:8.8::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS E4S (v.8.8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:rhel_tus:8.8::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS TUS (v.8.8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:rhel_e4s:9.0::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS E4S (v.9.0)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:rhel_e4s:9.2::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS E4S (v.9.2)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:rhel_eus:9.4::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS EUS (v.9.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:rhel_eus:9.6::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS EUS (v.9.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:9::baseos'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux BaseOS (v. 9)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux_eus:10.0'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10.1', 'cpe:/o:redhat:enterprise_linux:10.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8::crb'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux CRB (v. 8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.4::crb'], 'vendor': 'Red Hat', 'product': 'Red Hat CodeReady Linux Builder EUS (v.9.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.6::crb'], 'vendor': 'Red Hat', 'product': 'Red Hat CodeReady Linux Builder EUS (v.9.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9::crb'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:ai_inference_server:3.2::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat AI Inference Server 3.2', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:ai_inference_server:3.3::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat AI Inference Server 3.3', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux_ai:3.3::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AI 3.3', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:hummingbird:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Hardened Images', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhui:5::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Update Infrastructure 5', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 6', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 7', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux_ai:3'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AI (RHEL AI) 3', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8', 'defaultStatus': 'unaffected'}] Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-825 Added Reference https://access.redhat.com/errata/RHSA-2026:10117 Added Reference https://access.redhat.com/errata/RHSA-2026:10140 Added Reference https://access.redhat.com/errata/RHSA-2026:10141 Added Reference https://access.redhat.com/errata/RHSA-2026:10711 Added Reference https://access.redhat.com/errata/RHSA-2026:10745 Added Reference https://access.redhat.com/errata/RHSA-2026:10774 Added Reference https://access.redhat.com/errata/RHSA-2026:10949 Added Reference https://access.redhat.com/errata/RHSA-2026:10950 Added Reference https://access.redhat.com/errata/RHSA-2026:11062 Added Reference https://access.redhat.com/errata/RHSA-2026:11077 Added Reference https://access.redhat.com/errata/RHSA-2026:11768 Added Reference https://access.redhat.com/errata/RHSA-2026:13692 Added Reference https://access.redhat.com/errata/RHSA-2026:13812 Added Reference https://access.redhat.com/errata/RHSA-2026:14652 Added Reference https://access.redhat.com/errata/RHSA-2026:14653 Added Reference https://access.redhat.com/errata/RHSA-2026:14656 Added Reference https://access.redhat.com/errata/RHSA-2026:16699 Added Reference https://access.redhat.com/errata/RHSA-2026:17525 Added Reference https://access.redhat.com/errata/RHSA-2026:17619 Added Reference https://access.redhat.com/errata/RHSA-2026:19019 Added Reference https://access.redhat.com/errata/RHSA-2026:19064 Added Reference https://access.redhat.com/errata/RHSA-2026:19175 Added Reference https://access.redhat.com/errata/RHSA-2026:19176 Added Reference https://access.redhat.com/errata/RHSA-2026:19177 Added Reference https://access.redhat.com/errata/RHSA-2026:19216 Added Reference https://access.redhat.com/errata/RHSA-2026:19549 Added Reference https://access.redhat.com/errata/RHSA-2026:19570 Added Reference https://access.redhat.com/errata/RHSA-2026:19571 Added Reference https://access.redhat.com/errata/RHSA-2026:19576 Added Reference https://access.redhat.com/errata/RHSA-2026:19590 Added Reference https://access.redhat.com/errata/RHSA-2026:21275 Added Reference https://access.redhat.com/errata/RHSA-2026:21682 Added Reference https://access.redhat.com/errata/RHSA-2026:25096 Added Reference https://access.redhat.com/errata/RHSA-2026:26187 Added Reference https://access.redhat.com/errata/RHSA-2026:30078 Added Reference https://access.redhat.com/errata/RHSA-2026:30087 Added Reference https://access.redhat.com/errata/RHSA-2026:30088 Added Reference https://access.redhat.com/errata/RHSA-2026:30089 Added Reference https://access.redhat.com/errata/RHSA-2026:8822 Added Reference https://access.redhat.com/errata/RHSA-2026:8824 Added Reference https://access.redhat.com/errata/RHSA-2026:9228 Added Reference https://access.redhat.com/security/cve/CVE-2026-6100 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2457932 Added Reference https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6100.json -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/python/cpython', 'vendor': 'Python Software Foundation', 'product': 'CPython', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.13.14', 'versionType': 'python'}, {'status': 'affected', 'version': '3.14.0a1', 'lessThan': '3.14.5rc1', 'versionType': 'python'}, {'status': 'affected', 'version': '3.15.0a1', 'lessThan': '3.15.0b1', 'versionType': 'python'}], 'defaultStatus': 'unaffected'}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-6100', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-04-13T19:21:03.412763Z'} -
CVE Modified by [email protected]
Apr. 14, 2026
Action Type Old Value New Value Added Reference https://github.com/python/cpython/commit/47128e64f98c3a20271138a98c2922bea2a3ee0e Added Reference https://github.com/python/cpython/commit/e20c6c9667c99ecaab96e1a2b3767082841ffc8b -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Apr. 13, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/04/13/10 -
New CVE Received by [email protected]
Apr. 13, 2026
Action Type Old Value New Value Added Description Use-after-free (UAF) was possible in the `lzma.LZMADecompressor`, `bz2.BZ2Decompressor`, and `gzip.GzipFile` 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 fix cleans up the dangling pointer in this specific error condition. 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()`, `bz2.decompress()`, `gzip.decompress()`, and `zlib.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. Added CVSS V4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-787 Added CWE CWE-416 Added Reference https://github.com/python/cpython/commit/6a5f79c8d7bbf22b083b240910c7a8781a59437d Added Reference https://github.com/python/cpython/commit/8fc66aef6d7b3ae58f43f5c66f9366cc8cbbfcd2 Added Reference https://github.com/python/cpython/commit/c3cf71c3366fe49acb776a639405c0eea6169c20 Added Reference https://github.com/python/cpython/issues/148395 Added Reference https://github.com/python/cpython/pull/148396 Added Reference https://mail.python.org/archives/list/[email protected]/thread/HTWB2Z6KT5QQX4RYEZAFININDHNOSIF3/