Summary
Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities: CVE-2026-19672: The tarfile module's tar and data extraction filters created directories outside the destination for members whose name leaves the destination and returns to it, such as ../evil/../dest/sub/file. The containment check used the resolved path, but intermediate directories were created from the name as given. Only empty directories are created outside the destination. Member contents are still extracted inside it. To return to the destination the member's name must contain the destination directory's own final component, so extraction into a secure randomised directory is not affected. This affects POSIX platforms only. On Windows, .. components are collapsed before the path reaches the filesystem, so the directories outside the destination are never created. CVE-2026-19553: ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be silently skipped. This defect could lead to programs where certificate hostname verification *appeared* to be succeeding with SSLContext.check_hostname = True and no ValueError being raised due to misconfiguration. If the program passes a server_hostname value that isn't an empty string or None to any of these APIs then certificate hostname verification proceeds as expected and the program is not affected by this vulnerability. Mitigating this vulnerability doesn't require updating Python or applying the patch. To mitigate, pass a valid non-None and non-empty server_hostname value to SSLContext.wrap_bio(), asyncio.create_connection(), or asyncio.loop.start_tls() and certificate hostname verification will proceed as expected. Upgrading to the latest version of Python or applying the patch only changes the behavior from silently skipping hostname verification to raising a ValueError, similar to SSLContext.wrap_socket(), when server_hostname isn't supplied. CVE-2026-19445: A remote, unauthenticated TLS client can make a server crash or call through a freed pointer if its sni_callback assigns a different context to SSLSocket.context (the documented way to select a certificate per server name) and nothing else keeps the original ssl.SSLContext alive. Typical cases are servers that create an SSLContext per connection or replace it while connections are open; servers that wrap their listening socket with it are not affected. Mitigation: keep a reference to every SSLContext that sets sni_callback for the lifetime of the server. TLS clients are not affected. CVE-2026-17084: The "stringprep" module didn't process characters from RFC 3454 tables B.2 or B.3 correctly: the latest Unicode codepoint attributes were used instead of the specified Unicode 3.2.0. This behavior would cause mismatches when processing domain names using IDNA 2003 (the "idna" codec) and the in_table_b2() function of the "stringprep" module. This only affects domain names containing characters that were not previously registered or had their Unicode attributes such as case-folding behavior updated since Unicode 3.2.0. CVE-2026-15806: The HTTPPasswordMgr class in the urllib.request module, along with its subclasses HTTPPasswordMgrWithDefaultRealm and HTTPPasswordMgrWithPriorAuth, did not take the URL scheme into account when matching stored credentials against a requested URL. Credentials added for an https:// URL were also used for requests to the same host over http://, so an attacker able to redirect or downgrade a client to plain HTTP (for example, via an HTTPS-to-HTTP redirect or an on-path position) could capture credentials in cleartext. Credentials added for http:// URLs could likewise be sent over https://. Credential matching is now scoped by URL scheme. Credentials registered with a URL that includes a scheme are only used for requests with the same scheme. Credentials registered with a bare authority (such as example.com or example.com:8080) continue to match any scheme, preserving compatibility with existing code, including proxy authentication. Users who cannot upgrade immediately can mitigate by ensuring that applications never make plain http:// requests to hosts for which credentials are registered, for example by not following redirects to http:// URLs. CVE-2026-15310: When decompressing crafted zip files using the bzip/LZMA/Zstandard compressions, Python could use an attacker-controlled size to pre-allocate memory, possibly resulting in memory exhaustion.
Fixed packages 16
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux · 2023 | python3.14 | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-debug | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-debuginfo | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-debugsource | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-devel | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-freethreading | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-freethreading-debug | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-freethreading-devel | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-freethreading-idle | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-freethreading-libs | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-freethreading-test | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-freethreading-tkinter | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-idle | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-libs | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-test | 0:3.14.8-1.amzn2023.0.1 |
| Amazon Linux · 2023 | python3.14-tkinter | 0:3.14.8-1.amzn2023.0.1 |
Vulnerabilities 6
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Critical 9.2CVE-2026-19445 Public exploit
Use-after-free of a server-side SSLContext when sni_callback switches contexts
A remote, unauthenticated TLS client can make a server crash or call through a freed pointer if its sni_callback assigns a different context to SSLSocket.context (the documented way to select a certificate per server name) and nothing else keeps the original …
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High 7.6CVE-2026-19553 Public exploit
SSLContext.wrap_bio() missing validation of server_hostname parameter
ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if ssl.SSLContext.check_hostname was set. Due to a missing parameter check in SSLObject, if the server_hostname argument isn't supplied then hostname verification would be si…
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Medium 6.3
tarfile extraction filter bypass allows creation of directories outside the destination
The tarfile module's tar and data extraction filters created directories outside the destination for members whose name leaves the destination and returns to it, such as ../evil/../dest/sub/file. The containment check used the resolved path, but intermediate …
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Medium 6.0
`HTTPPasswordMgr` can send saved HTTPS credentials via HTTP because of incorrect scheme matching
The HTTPPasswordMgr class in the urllib.request module, along with its subclasses HTTPPasswordMgrWithDefaultRealm and HTTPPasswordMgrWithPriorAuth, did not take the URL scheme into account when matching stored credentials against a requested URL. Credentials …
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Medium 6.0
stringprep.map_table_b2() deviates from RFC 3454 Table B.2
The "stringprep" module didn't process characters from RFC 3454 tables B.2 or B.3 correctly: the latest Unicode codepoint attributes were used instead of the specified Unicode 3.2.0. This behavior would cause mismatches when processing domain names using IDNA…
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Low 2.1
zipfile: bzip2/LZMA/Zstandard members decompress without a max_length bound, defeating chunked-read memory limits
When decompressing crafted zip files using the bzip/LZMA/Zstandard compressions, Python could use an attacker-controlled size to pre-allocate memory, possibly resulting in memory exhaustion.
References
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-15310.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-15806.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-17084.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-19445.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-19553.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-19672.html