Bug 2536814 - CVE-2026-86861 pgadmin4: pgAdmin 4: Arbitrary file write via symbolic link following in File Manager [fedora-all]
Summary: CVE-2026-86861 pgadmin4: pgAdmin 4: Arbitrary file write via symbolic link fo...
Keywords:
Status: ON_QA
Alias: None
Product: Fedora
Classification: Fedora
Component: pgadmin4
Version: rawhide
Hardware: Unspecified
OS: Unspecified
medium
medium
Target Milestone: ---
Assignee: Sandro Mani
QA Contact:
URL:
Whiteboard: {"flaws": ["c160de01-bc2f-407a-a297-7...
Depends On:
Blocks: CVE-2026-86861
TreeView+ depends on / blocked
 
Reported: 2026-09-17 19:51 UTC by Vladimir Vasilev
Modified: 2026-09-19 02:23 UTC (History)
1 user (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Type: ---
Embargoed:


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Description Vladimir Vasilev 2026-09-17 19:51:50 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

pgAdmin 4's File Manager save_file endpoint, which backs saving from the Query Tool and ERD, validated the requested path with Filemanager.check_access_permission() and then opened the file for writing with a plain open() call. CVE-2026-7819 had previously hardened the separate file upload path by opening its target with O_NOFOLLOW, so that the kernel refuses to follow a symbolic link at the final path component, but save_file was left on an unprotected open(). A symbolic link already present when the check ran was rejected by the check itself; the remaining exposure was a link substituted at the final path component in the interval between the check and the write, at which point the write followed the link and landed outside the user's storage directory, creating or overwriting an arbitrary file as the operating-system account running pgAdmin.

Exploitation requires the ability to create or replace a symbolic link inside the requesting user's storage directory. pgAdmin exposes no interface that creates symbolic links, so this requires filesystem access to the pgAdmin host or to a shared or network-mounted storage backend, together with winning the timing window. The reporter did not achieve a write against a released version, having attempted approximately 63,000 racing requests without success; the reported defect is the uncovered write path rather than a demonstrated sandbox escape.

The fix routes save_file's write through the same O_NOFOLLOW-protected helper already used by the upload path, so both File Manager write sinks carry identical kernel-enforced protection, and reports a symbolic-link refusal explicitly instead of surfacing the underlying system error text. Note that files created by save_file are now given mode 0600, inheriting the behaviour introduced for uploads. The protection covers the final path component; substitution of an intermediate directory component is not addressed by this change.

This issue affects pgAdmin 4: from the introduction of the containment check in the File Manager save path before 9.18.

Comment 1 Fedora Update System 2026-09-18 19:45:15 UTC
FEDORA-2026-c070c47328 (pgadmin4-9.18-1.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-c070c47328

Comment 2 Fedora Update System 2026-09-18 19:45:26 UTC
FEDORA-2026-dddd2792e3 (pgadmin4-9.18-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-dddd2792e3

Comment 3 Fedora Update System 2026-09-18 19:45:36 UTC
FEDORA-2026-035cf95dc5 (pgadmin4-9.18-1.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-035cf95dc5

Comment 4 Fedora Update System 2026-09-19 01:40:28 UTC
FEDORA-2026-035cf95dc5 has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-035cf95dc5`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-035cf95dc5

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 5 Fedora Update System 2026-09-19 02:19:20 UTC
FEDORA-2026-c070c47328 has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-c070c47328`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-c070c47328

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 6 Fedora Update System 2026-09-19 02:23:07 UTC
FEDORA-2026-dddd2792e3 has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-dddd2792e3`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-dddd2792e3

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.


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