EUVD-2026-51279
GHSA-6m77-jgxr-wx9c
Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Network-accessible REST service with no built-in auth (PR:N, AV:N); impact scoped to Tika server processing with low C/I/A as the bypass enables restricted endpoint access but not direct system compromise.
Primary rating from Vendor (CNA).
CVSS VectorVendor
Lifecycle Timeline
3Description PRE-NVD
AnalysisAI
The /unpack endpoint in Apache Tika's server component (tika-server 4.0.0-alpha-1) fails to enforce the operator-configured enableUnsecureFeatures=false security control, classified as Improper Protection of Alternate Path. This means the /unpack endpoint remains fully operational even when administrators have explicitly disabled unsafe features, bypassing the intended security boundary and allowing archive extraction or untrusted content processing through a restricted interface. No public exploit code has been identified and the vulnerability is confined to a pre-production alpha release, significantly limiting real-world exposure.
Technical ContextAI
Apache Tika is a content analysis toolkit that exposes document parsing and extraction capabilities via a REST API through tika-server (org.apache.tika:tika-server). The server includes a security flag, enableUnsecureFeatures (also expressed as unsecureFeatures), that gates access to potentially dangerous endpoints - including /pipes, /async, /status, and now confirmed /unpack - which can expose the service to risks such as resource exhaustion, SSRF, zip-slip path traversal, or triggering parser exploits on attacker-controlled content. The root cause is CWE-424 (Improper Protection of Alternate Path): the /unpack endpoint contains a code path that does not check the enableUnsecureFeatures flag, so the flag's intended restriction is silently bypassed. Context from the contemporaneous Tika 3.3.2 release confirms this pattern - that release backported analogous tightening for /pipes, /async, and /status to the stable 3.x branch, indicating /unpack was identified as requiring the same treatment in the 4.x alpha series.
RemediationAI
Upgrade to Apache Tika 4.0.0-beta-1 or a later release, which contains the fix for the /unpack endpoint authorization bypass; this release is available from the Apache Tika download page at https://tika.apache.org/. Since 4.0.0-alpha-1 is pre-production alpha software, any deployment in a non-experimental context should be treated as a misconfiguration regardless of this CVE, and migration to a stable or beta release is warranted on those grounds alone. As a compensating control before patching, restrict network access to the tika-server process using host-based firewall rules or a reverse proxy with strict ACLs so that only explicitly trusted clients or internal services can reach any tika-server endpoint; this limits the blast radius of the /unpack bypass and aligns with tika-server's intended deployment model of internal-only exposure. Note that restricting the /unpack path specifically at the proxy layer is a targeted option, though it may break legitimate workflows that rely on the endpoint.
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Same weakness CWE-424 – Improper Protection of Alternate Path
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External POC / Exploit Code
Leaving vuln.today