Apache Tika: Improper Protection of Alternate Path
CVE-2026-66756 is a critical-severity improper protection of alternate path vulnerability in Apache Tika from Apache, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 4.0.0-beta-1 as the first without the flaw, so updating Apache Tika to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.75% chance of exploitation within 30 days, higher than 55% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Apache Tika to 4.0.0-beta-1 or a later version.
- Read the advisory on lists.apache.org for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apache | Apache Tika | 4.0.0-alpha-1 up to, but not including, 4.0.0-beta-1 | 4.0.0-beta-1 |
| Apache | Tika | 4.0.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 6.9 | Medium | CNA (apache.org) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
Improper Protection of Alternate Path vulnerability in Apache Tika. This issue affects Apache Tika: from 4.0.0-alpha-1 before 4.0.0-beta-1. Users are recommended to upgrade to version 4.0.0-beta-1, which fixes the issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Protection of Alternate Path
The product does not sufficiently protect all possible paths that a user can take to access restricted functionality or resources.
How developers prevent this class of flaw
- Deploy different layers of protection to implement security in depth.
More Improper Protection of Alternate Path vulnerabilities (CWE-424)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- openwall.com/lists/oss-security/2026/07/30/24Mailing List, Third Party Advisory
Other vulnerabilities in Apache Tika
- 7.5 High severity
Recent Improper Protection of Alternate Path vulnerabilities
- 8.2 High severity
- 7.8 High severity
- 8.1 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.5 High severity
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