Link Following (Symlink)Weakness · CWE-59

CVE-2026-53783

HIGH · 8.1 CVSS v3.1 Published 2026-08-13
No fix yet
No fix has been published. The vendor has not shipped a fixed release or patch. You remain exposed.
See remediation →
87/100
Remediation priority · High
Remotely reachable Zero-click 6 days old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
rsync before 3.5.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability in the rrsync restricted shell wrapper that allows authenticated clients to escape enforced directory restrictions by substituting a symlink for a path component after validation but before transfer processing. Attackers can additionally leverage unrestricted flags such as --copy-unsafe-links, -D, and --log-file through rrsync to read or write files outside the permitted directory subtree.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-59

A file operation follows a symbolic link without checking where it actually points, so an attacker who can plant or swap a link redirects the operation to a file they should not be able to touch. It is a common local privilege-escalation primitive. Remediation is resolving and validating the real target path, and avoiding operations on attacker-controllable links.

General guidance for the link following (symlink) class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Recommended fix High confidence

rsync 3.5.0 or later

  1. 1. Identify the rsync version currently installed on systems using `rsync --version`
  2. 2. If running rsync version prior to 3.5.0, download and install version 3.5.0 or later from the official rsync website (rsync.samba.org)
  3. 3. Review all rrsync wrapper scripts in use and ensure they are updated to the latest version that ships with rsync 3.5.0+
  4. 4. Verify the restricted shell configuration using rrsync properly enforces directory restrictions after upgrade
  5. 5. Audit allowed rrsync command-line flags and remove unsafe flags like --copy-unsafe-links, -D (unless needed), and --log-file from restricted configurations
  6. 6. Test the fix by attempting the symlink-based escape described in the CVE to confirm mitigation
Caveat Ensure any scripts relying on specific pre-3.5.0 rrsync behavior are tested, as minor behavioral changes may exist in the upgrade

Generated from the published advisory — verify against the referenced sources before acting.

No vendor fix exists The vendor has not published a patch for this.

There is no version to upgrade to and no patch to apply. Every affected install stays exposed until the vendor ships a fix — or somebody else builds one.

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Scan for this in your stack

Free · runs locally
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-53783 in production — separate from our analysis above.

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What this is

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