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VulnerabilityPublished Updated

CVE-2026-40303: openziti zrok · Uncontrolled Resource Consumption

Affects openziti zrokSource CVE Database V5

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Not known to be exploited · CVSS 7.5 High : upgrade to 2.0.1 soon.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 2.0.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 17 Apr 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

What to do

Upgrade zrok and github.com/openziti/zrok to 2.0.1.

Affected software

ProductAffectedFixed in
openzitizrokAffected
  • <2.0.1
Fixed in
  • 2.0.1
Gogithub.com/openziti/zrokpkg:golang/github.com/openziti/zrokOther threatsAffected
  • <2.0.1
Fixed in
  • 2.0.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Version 2.0.1 of openziti zrok patches this vulnerability. Users should upgrade to version 2.0.1 or later to remediate the issue. Since no official remediation level or patch link is provided beyond this version information, verify with the vendor's advisory for the latest updates. Until patched, consider restricting access to OAuth-protected proxy shares or implementing rate limiting to reduce exposure.

Description

zrok is software for sharing web services, files, and network resources. Prior to version 2.0.1, endpoints.GetSessionCookie parses an attacker-supplied cookie chunk count and calls make([]string, count) with no upper bound before any token validation occurs. The function is reached on every request to an OAuth-protected proxy share, allowing an unauthenticated remote attacker to trigger gigabyte-scale heap allocations per request, leading to process-level OOM termination or repeated goroutine panics. Both publicProxy and dynamicProxy are affected. Version 2.0.1 patches the issue.

References

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