Python 2.7, end of life since 1 January 2020
Python 2.7.18 vulnerabilities
Python 2.7.18 ships with CentOS 8, Amazon Linux 2 and Debian 11. The US National Vulnerability Database lists 35 vulnerabilities for this version, 2 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.
- 35known vulnerabilities
- 2critical
- 17high
- 0exploited in the wild
What you can do
Keep Python 2.7.18, 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 35 known vulnerabilities in Python 2.7.18
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-2007-4559 | 9.8 | Critical | 2007-08-28 | 3.6.16 | Directory traversal vulnerability in the (1) extract and (2) extractall functions in the tarfile module in Python allows user-assisted remote attackers to overwrite arbitrary files via a .. (dot dot) sequence in filenames in a TAR archive, a related issue to CVE-2001-1267. |
| CVE-2022-48565 | 9.8 | Critical | 2023-08-22 | 3.6.13 | An XML External Entity (XXE) issue was discovered in Python through 3.9.1. The plistlib module no longer accepts entity declarations in XML plist files to avoid XML vulnerabilities. |
| CVE-2017-17522 | 8.8 | High | 2017-12-14 | n/a | Lib/webbrowser.py in Python through 3.6.3 does not validate strings before launching the program specified by the BROWSER environment variable, which might allow remote attackers to conduct argument-injection attacks via a crafted URL. NOTE: a software maintainer indicates that exploitation is impossible because the code relies on subprocess.Popen and the default shell=False setting |
| 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-2022-0391 | 7.5 | High | 2022-02-09 | 3.6.14 | A flaw was found in Python, specifically within the urllib.parse module. This module helps break Uniform Resource Locator (URL) strings into components. The issue involves how the urlparse method does not sanitize input and allows characters like '\r' and '\n' in the URL path. This flaw allows an attacker to input a crafted URL, leading to injection attacks. This flaw affects Python versions prior to 3.10.0b1, 3.9.5, 3.8.11, 3.7.11 and 3.6.14. |
| CVE-2022-45061 | 7.5 | High | 2022-11-09 | n/a | An issue was discovered in Python before 3.11.1. An unnecessary quadratic algorithm exists in one path when processing some inputs to the IDNA (RFC 3490) decoder, such that a crafted, unreasonably long name being presented to the decoder could lead to a CPU denial of service. Hostnames are often supplied by remote servers that could be controlled by a malicious actor; in such a scenario, they could trigger excessive CPU consumption on the client attempting to make use of an attacker-supplied supposed hostname. For example, the attack payload could be placed in the Location header of an HTTP response with status code 302. A fix is planned in 3.11.1, 3.10.9, 3.9.16, 3.8.16, and 3.7.16. |
| CVE-2022-48560 | 7.5 | High | 2023-08-22 | 3.6.11 | A use-after-free exists in Python through 3.9 via heappushpop in heapq. |
| CVE-2023-24329 | 7.5 | High | 2023-02-17 | 3.7.17 | An issue in the urllib.parse component of Python before 3.11.4 allows attackers to bypass blocklisting methods by supplying a URL that starts with blank characters. |
| 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-2024-6232 | 7.5 | High | 2024-09-03 | 3.8.20 | There is a MEDIUM severity vulnerability affecting CPython. Regular expressions that allowed excessive backtracking during tarfile.TarFile header parsing are vulnerable to ReDoS via specifically-crafted tar archives. |
| CVE-2024-7592 | 7.5 | High | 2024-08-19 | 3.8.20 | There is a LOW severity vulnerability affecting CPython, specifically the 'http.cookies' standard library module. When parsing cookies that contained backslashes for quoted characters in the cookie value, the parser would use an algorithm with quadratic complexity, resulting in excess CPU resources being used while parsing the value. |
| 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-2015-5652 | 7.2 | High | 2015-10-06 | n/a | Untrusted search path vulnerability in python.exe in Python through 3.5.0 on Windows allows local users to gain privileges via a Trojan horse readline.pyd file in the current working directory. NOTE: the vendor says "It was determined that this is a longtime behavior of Python that cannot really be altered at this point." |
| CVE-2022-26488 | 7.0 | High | 2022-03-10 | n/a | In Python before 3.10.3 on Windows, local users can gain privileges because the search path is inadequately secured. The installer may allow a local attacker to add user-writable directories to the system search path. To exploit, an administrator must have installed Python for all users and enabled PATH entries. A non-administrative user can trigger a repair that incorrectly adds user-writable paths into PATH, enabling search-path hijacking of other users and system services. This affects Python (CPython) through 3.7.12, 3.8.x through 3.8.12, 3.9.x through 3.9.10, and 3.10.x through 3.10.2. |
| CVE-2017-18207 | 6.5 | Medium | 2018-03-01 | n/a | The Wave_read._read_fmt_chunk function in Lib/wave.py in Python through 3.6.4 does not ensure a nonzero channel value, which allows attackers to cause a denial of service (divide-by-zero and exception) via a crafted wav format audio file. NOTE: the vendor disputes this issue because Python applications "need to be prepared to handle a wide variety of exceptions. |
| CVE-2021-3733 | 6.5 | Medium | 2022-03-10 | 3.6.14 | There's a flaw in urllib's AbstractBasicAuthHandler class. An attacker who controls a malicious HTTP server that an HTTP client (such as web browser) connects to, could trigger a Regular Expression Denial of Service (ReDOS) during an authentication request with a specially crafted payload that is sent by the server to the client. The greatest threat that this flaw poses is to application availability. |
| CVE-2022-48564 | 6.5 | Medium | 2023-08-22 | 3.6.13 | read_ints in plistlib.py in Python through 3.9.1 is vulnerable to a potential DoS attack via CPU and RAM exhaustion when processing malformed Apple Property List files in binary format. |
| 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-2021-23336 | 5.9 | Medium | 2021-02-15 | 3.6.13 | The package python/cpython from 0 and before 3.6.13, from 3.7.0 and before 3.7.10, from 3.8.0 and before 3.8.8, from 3.9.0 and before 3.9.2 are vulnerable to Web Cache Poisoning via urllib.parse.parse_qsl and urllib.parse.parse_qs by using a vector called parameter cloaking. When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This can result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter. |
| CVE-2022-48566 | 5.9 | Medium | 2023-08-22 | 3.6.13 | An issue was discovered in compare_digest in Lib/hmac.py in Python through 3.9.1. Constant-time-defeating optimisations were possible in the accumulator variable in hmac.compare_digest. |
| 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-2023-27043 | 5.3 | Medium | 2023-04-19 | n/a | The email module of Python through 3.11.3 incorrectly parses e-mail addresses that contain a special character. The wrong portion of an RFC2822 header is identified as the value of the addr-spec. In some applications, an attacker can bypass a protection mechanism in which application access is granted only after verifying receipt of e-mail to a specific domain (e.g., only @company.example.com addresses may be used for signup). This occurs in email/_parseaddr.py in recent versions of Python. |
| CVE-2023-40217 | 5.3 | Medium | 2023-08-25 | 3.8.18 | An issue was discovered in Python before 3.8.18, 3.9.x before 3.9.18, 3.10.x before 3.10.13, and 3.11.x before 3.11.5. It primarily affects servers (such as HTTP servers) that use TLS client authentication. If a TLS server-side socket is created, receives data into the socket buffer, and then is closed quickly, there is a brief window where the SSLSocket instance will detect the socket as "not connected" and won't initiate a handshake, but buffered data will still be readable from the socket buffer. This data will not be authenticated if the server-side TLS peer is expecting client certificate authentication, and is indistinguishable from valid TLS stream data. Data is limited in size to the amount that will fit in the buffer. (The TLS connection cannot directly be used for data exfiltration because the vulnerable code path requires that the connection be closed on initialization of the SSLSocket.) |
| 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-2026-4360 | 5.3 | Medium | 2026-06-30 | 3.1.5 | In the Tarfile.extract() function, the filter parameter is not passed properly when extracting hardlinks. An affected system that extracts content from untrusted tar files could end up writing files with an unexpected uid/gid despite the user passing filter='data' to the extract() function. |
| 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(). |