Nomad: Symlink following allows writes outside the allocation directory
Summary
HashiCorp Nomad and Nomad Enterprise follow symbolic links when writing dispatch payloads and executor logs. A user with job submission rights can use a malicious workload to create, overwrite or append to files outside the allocation directory. If the Nomad client agent runs as root, this can lead to code execution as root on the client host.
Affected
- Nomad: up to 2.1.0 according to the vendor advisory (CNA range: 0.3.0 to before 2.1.1)
- Nomad Enterprise: up to 2.0.7 according to the vendor advisory (CNA range: 0.3.0 to before 2.1.0)
- The executor log variant only affects workloads using the exec or java drivers on Linux
Fixed in
- Nomad 2.1.1 (per the vendor advisory and CNA record)
- Nomad Enterprise 2.1.0, 1.11.12 and 1.10.18
Workaround
- Unknown. The advisory describes no vendor workaround; the upgrade is the fix.
- Interim measure: restrict who can submit or dispatch jobs.
- Interim measure: review which client hosts run the Nomad agent as root.
Exploitation
- No public proof of concept found.
- Not known to be exploited in the wild.
- CISA SSVC: exploitation none, not automatable, partial technical impact.
- EPSS: 0.13 %.
Our recommendation
- Check whether Nomad is used in your environment at all.
- Upgrade client agents, not only servers, to the fixed versions. Confirm the exact fixed Community version in the HashiCorp release notes, as sources differ.
- Limit job submission and dispatch rights to trusted users.
- Prioritise clusters with shared teams or third-party workloads, and agents running as root.
- Monitor for unexpected changes to host files.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- HashiCorp advisory HCSEC-2026-52 discuss.hashicorp.com
- HashiCorp advisory HCSEC-2026-53 (same fixed versions) discuss.hashicorp.com
- OffSeq threat entry CVE-2026-107347 radar.offseq.com
- Strix CVE entry CVE-2026-107347 www.strix.ai
- Ubuntu OSV entry CVE-2026-107347 vulners.com
- VulDB entry 428709 vuldb.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 11:50.
Original description (NVD)
HashiCorp Nomad and Nomad Enterprise are vulnerable to symlink following during dispatch payload and executor log writes that may allow a malicious workload to modify files outside its allocation directory. When the client agent runs as root, this could lead to code execution as root on the client host. This vulnerability (CVE-2026-107347) is fixed in Nomad 2.1.1 and Nomad Enterprise 2.1.0, 1.11.12, and 1.10.18.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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