There are 15 open security issues in trixie.
5 important issues:
- CVE-2025-11468:
When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized.
- CVE-2025-12781:
When passing data to the b64decode(), standard_b64decode(), and urlsafe_b64decode() functions in the "base64" module the characters "+/" will always be accepted, regardless of the value of "altchars" parameter, typically used to establish an "alternative base64 alphabet" such as the URL safe alphabet. This behavior matches what is recommended in earlier base64 RFCs, but newer RFCs now recommend either dropping characters outside the specified base64 alphabet or raising an error. The old behavior has the possibility of causing data integrity issues. This behavior can only be insecure if your application uses an alternate base64 alphabet (without "+/"). If your application does not use the "altchars" parameter or the urlsafe_b64decode() function, then your application does not use an alternative base64 alphabet. The attached patches DOES NOT make the base64-decode behavior raise an error, as this would be a change in behavior and break existing programs. Instead, the patch deprecates the behavior which will be replaced with the newly recommended behavior in a future version of Python. Users are recommended to mitigate by verifying user-controlled inputs match the base64 alphabet they are expecting or verify that their application would not be affected if the b64decode() functions accepted "+" or "/" outside of altchars.
- CVE-2025-15282:
User-controlled data URLs parsed by urllib.request.DataHandler allow injecting headers through newlines in the data URL mediatype.
- CVE-2025-15366:
The imaplib module, when passed a user-controlled command, can have additional commands injected using newlines. Mitigation rejects commands containing control characters.
- CVE-2025-15367:
The poplib module, when passed a user-controlled command, can have additional commands injected using newlines. Mitigation rejects commands containing control characters.
10 issues left for the package maintainer to handle:
- CVE-2025-6069:
(needs triaging)
The html.parser.HTMLParser class had worse-case quadratic complexity when processing certain crafted malformed inputs potentially leading to amplified denial-of-service.
- CVE-2025-6075:
(needs triaging)
If the value passed to os.path.expandvars() is user-controlled a performance degradation is possible when expanding environment variables.
- CVE-2025-8194:
(needs triaging)
There is a defect in the CPython “tarfile” module affecting the “TarFile” extraction and entry enumeration APIs. The tar implementation would process tar archives with negative offsets without error, resulting in an infinite loop and deadlock during the parsing of maliciously crafted tar archives. This vulnerability can be mitigated by including the following patch after importing the “tarfile” module: https://gist.github.com/sethmlarson/1716ac5b82b73dbcbf23ad2eff8b33e1
- CVE-2025-8291:
(needs triaging)
The 'zipfile' module would not check the validity of the ZIP64 End of Central Directory (EOCD) Locator record offset value would not be used to locate the ZIP64 EOCD record, instead the ZIP64 EOCD record would be assumed to be the previous record in the ZIP archive. This could be abused to create ZIP archives that are handled differently by the 'zipfile' module compared to other ZIP implementations. Remediation maintains this behavior, but checks that the offset specified in the ZIP64 EOCD Locator record matches the expected value.
- CVE-2026-0672:
(needs triaging)
When using http.cookies.Morsel, user-controlled cookie values and parameters can allow injecting HTTP headers into messages. Patch rejects all control characters within cookie names, values, and parameters.
- CVE-2026-0865:
(needs triaging)
User-controlled header names and values containing newlines can allow injecting HTTP headers.
- CVE-2026-1299:
(needs triaging)
The email module, specifically the "BytesGenerator" class, didn’t properly quote newlines for email headers when serializing an email message allowing for header injection when an email is serialized. This is only applicable if using "LiteralHeader" writing headers that don't respect email folding rules, the new behavior will reject the incorrectly folded headers in "BytesGenerator".
- CVE-2025-12084:
(needs triaging)
When building nested elements using xml.dom.minidom methods such as appendChild() that have a dependency on _clear_id_cache() the algorithm is quadratic. Availability can be impacted when building excessively nested documents.
- CVE-2025-13836:
(needs triaging)
When reading an HTTP response from a server, if no read amount is specified, the default behavior will be to use Content-Length. This allows a malicious server to cause the client to read large amounts of data into memory, potentially causing OOM or other DoS.
- CVE-2025-13837:
(needs triaging)
When loading a plist file, the plistlib module reads data in size specified by the file itself, meaning a malicious file can cause OOM and DoS issues
You can find information about how to handle these issues in the security team's documentation.
![[bug history graph]](https://qa.debian.org/data/bts/graphs/p/python3.13.png){kind=link}