High severity · published Sep 16, 2026
CVE-2026-85731
oras-go: Arbitrary file write outside file.Store root via symlink-chain bypass in tar extraction (pushDir)
8.8
CVSS
0.7%
EPSS
No
On KEV
Description
oras-go is a Go library for managing OCI artifacts. Prior to 2.6.2, content/file.Store extraction of OCI layers marked with io.deis.oras.content.unpack=true can write outside the store working directory. The pushDir path through extractTarDirectory and ensureLinkPath validates symlink targets lexically, resolveRelToBase skips its parent-symlink walk for root-level entries, and writeFile follows a terminal symlink when opening a regular file. A malicious archive can therefore create a symlink chain whose lexical target remains inside the extraction root but whose resolved target is an attacker-selected absolute path, then overwrite that target with a same-named regular-file entry even when AllowPathTraversalOnWrite is false. Pulling an attacker-controlled artifact can create or overwrite any file writable by the process and may lead to code execution. This issue is fixed in version 2.6.2.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 52% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OR
oras-go · oras-project
< 2.6.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-85731
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-85731
github.com
https://github.com/oras-project/oras-go/commit/adab2f25ea95ef4e6e41f50db9266a6701399422
github.com
https://github.com/oras-project/oras-go/releases/tag/v2.6.2
github.com
https://github.com/oras-project/oras-go/security/advisories/GHSA-m37j-52j7-pjw7
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