Python 3.8, end of life since 7 October 2024
Python 3.8.20 vulnerabilities
Python 3.8.20 is the last release of the 3.8 branch, end of life since 7 October 2024. The US National Vulnerability Database lists 16 vulnerabilities for this version, none of them critical. The Python project fixes flaws only in supported versions. Distributions backport those fixes while they are supported and stop at end of life.
- 16known vulnerabilities
- 0critical
- 8high
- 0exploited in the wild
What you can do
Keep Python 3.8.20, patched
We backport the security fixes to the Python you run, from your distribution's package or your own build, built and tested before delivery. A fix for a new vulnerability arrives within 48 hours of your order, or within 24 hours with priority delivery.
Upgrade
Move to a supported Python version once your code and its libraries can make the jump. Our fixes keep you safe while you plan it.
Assess first
Our assessment shows which vulnerabilities are real on your servers, what else is past end of life, and the remediation plan.
All 16 known vulnerabilities in Python 3.8.20
US National Vulnerability Database, 28 October 2026, highest score first. Fixed in: the first upstream release with the fix, where NVD records it. Exploited: listed in the CISA catalogue of known exploited vulnerabilities. Distribution builds may already include fixes for some of them.
| CVE | Score | Severity | Published | Fixed in | Description |
|---|---|---|---|---|---|
| CVE-2024-9287 | 7.8 | High | 2024-10-22 | 3.9.21 | A vulnerability has been found in the CPython `venv` module and CLI where path names provided when creating a virtual environment were not quoted properly, allowing the creator to inject commands into virtual environment "activation" scripts (ie "source venv/bin/activate"). This means that attacker-controlled virtual environments are able to run commands when the virtual environment is activated. Virtual environments which are not created by an attacker or which aren't activated before being used (ie "./venv/bin/python") are not affected. |
| CVE-2023-36632 | 7.5 | High | 2023-06-25 | n/a | The legacy email.utils.parseaddr function in Python through 3.11.4 allows attackers to trigger "RecursionError: maximum recursion depth exceeded while calling a Python object" via a crafted argument. This argument is plausibly an untrusted value from an application's input data that was supposed to contain a name and an e-mail address. NOTE: email.utils.parseaddr is categorized as a Legacy API in the documentation of the Python email package. Applications should instead use the email.parser.BytesParser or email.parser.Parser class. NOTE: the vendor's perspective is that this is neither a vulnerability nor a bug. The email package is intended to have size limits and to throw an exception when limits are exceeded; they were exceeded by the example demonstration code. |
| CVE-2025-13836 | 7.5 | High | 2025-12-01 | 3.10.20 | 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-2026-15308 | 7.5 | High | 2026-07-09 | 3.10.21 | The incremental HTML parser (html.parser.HTMLParser) allows for CPU denial-of-service through repeated unterminated markup declarations when processing uncontrolled data. |
| CVE-2026-3087 | 7.5 | High | 2026-04-27 | n/a | If `shutil.unpack_archive()` is given a ZIP archive with an absolute Windows path containing a drive (`C:\\...`) then the archive will be extracted outside the target directory which is different than other operating systems. Only Windows is affected by this vulnerability. |
| CVE-2026-3644 | 7.5 | High | 2026-03-16 | 3.13.13 | The fix for CVE-2026-0672, which rejected control characters in http.cookies.Morsel, was incomplete. The Morsel.update(), |= operator, and unpickling paths were not patched, allowing control characters to bypass input validation. Additionally, BaseCookie.js_output() lacked the output validation applied to BaseCookie.output(). |
| CVE-2026-4224 | 7.5 | High | 2026-03-16 | 3.10.0 | When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs. |
| CVE-2026-7210 | 7.5 | High | 2026-05-11 | 3.13.14 | `xml.parsers.expat` and `xml.etree.ElementTree` use insufficient entropy for Expat hash-flooding protection, which allows a crafted XML document to trigger hash flooding.\r\n\r\nFully mitigating this vulnerability requires both updating libexpat to 2.8.0 or later and applying this patch. |
| CVE-2026-6019 | 6.1 | Medium | 2026-04-22 | 3.13.14 | http.cookies.Morsel.js_output() returns an inline <script> snippet and only escapes " for JavaScript string context. It does not neutralize the HTML parser-sensitive sequence </script> inside the generated script element. Mitigation base64-encodes the cookie value to disallow escaping using cookie value. |
| CVE-2025-13837 | 5.5 | Medium | 2025-12-01 | 3.13.10 | 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 |
| CVE-2025-6075 | 5.5 | Medium | 2025-10-31 | 3.9.0 | If the value passed to os.path.expandvars() is user-controlled a performance degradation is possible when expanding environment variables. |
| CVE-2026-0864 | 5.5 | Medium | 2026-06-23 | 3.10.21 | When using the "configparser" module to write configuration files containing multi-line text values with carriage return characters (\r) the resulting file could be injected with unexpected keys and values if the attacker controls the written value. |
| CVE-2025-12084 | 5.3 | Medium | 2025-12-03 | 3.13.11 | 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-2025-12781 | 5.3 | Medium | 2026-01-21 | 3.13.10 | 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-2025-13462 | 3.3 | Low | 2026-03-12 | 3.13.13 | The "tarfile" module would still apply normalization of AREGTYPE (\x00) blocks to DIRTYPE, even while processing a multi-block member such as GNUTYPE_LONGNAME or GNUTYPE_LONGLINK. This could result in a crafted tar archive being misinterpreted by the tarfile module compared to other implementations. |
| CVE-2026-4519 | 3.3 | Low | 2026-03-20 | 3.13.13 | The webbrowser.open() API would accept leading dashes in the URL which could be handled as command line options for certain web browsers. New behavior rejects leading dashes. Users are recommended to sanitize URLs prior to passing to webbrowser.open(). |