Apache NiFi: Improper Handling of Highly Compressed Data (Data Amplification)
CVE-2026-68981 is a high-severity improper handling of highly compressed data (data amplification) vulnerability in Apache NiFi from Apache, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Apache NiFi versions: 1.5.0 through 2.10.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.74% chance of exploitation within 30 days, higher than 55% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Nifi to 2.11.0 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 NiFi | 1.5.0 through 2.10.0 | Not stated |
| Apache | Nifi | 1.5.0 up to, but not including, 2.11.0 | 2.11.0 |
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
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.8 | High | CNA (apache.org) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
Apache NiFi 1.5.0 through 2.10.0 support gzip-encoded HTTP requests for the application REST API using a Jersey encoding filter. The framework enforced a configurable maximum request size on the compressed payload rather than the decompressed output, allowing a malicious client to send crafted requests that could consume excessive amounts of memory. Upgrading to Apache NiFi 2.11.0 is the recommended mitigation, which relocates response compression to Jetty Server and disables decompression of gzip-encoded HTTP requests.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Highly Compressed Data (Data Amplification)
The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.
More Improper Handling of Highly Compressed Data (Data Amplification) vulnerabilities (CWE-409)
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/2026/08/03/13Mailing List, Third Party Advisory
Other vulnerabilities in Apache NiFi
- 7.1 High severity
- 7.5 High severity
- 9.1 Critical severity
- 9.8 Critical severity
- 7.2 High severity
- 7.2 High severity
Recent Improper Handling of Highly Compressed Data (Data Amplification) vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 8.7 High severity
- 8.2 High severity
- 7.5 High severity
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