Description
The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we inflate incoming data, the filter does not control the resulting size, and create a buffer no matter what.
Some compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size.
The fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception. It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes)
For application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted.
Here are the additional constructor:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound,
final int compressionLevel, final int maxDecompressedSize,
final long maxDecompressRatio, final long decompressRatioMinSize)
Also note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters:
CompressionFilter compressionFilter = new CompressionFilter()
.setCompressionLevel(Zlib.COMPRESSION_MAX)
.setMaxDecompressedSize(1_000_000)
.setMaxDecompressRatio(100).
.setDecompressRatioMinSize(100_000);
Applications using Apache MINA are advised to upgrade and configure their CompressionFilter instance.
Some compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size.
The fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception. It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes)
For application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted.
Here are the additional constructor:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound,
final int compressionLevel, final int maxDecompressedSize,
final long maxDecompressRatio, final long decompressRatioMinSize)
Also note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters:
CompressionFilter compressionFilter = new CompressionFilter()
.setCompressionLevel(Zlib.COMPRESSION_MAX)
.setMaxDecompressedSize(1_000_000)
.setMaxDecompressRatio(100).
.setDecompressRatioMinSize(100_000);
Applications using Apache MINA are advised to upgrade and configure their CompressionFilter instance.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Apache Software Foundation | Apache MINA | unaffected |
|
No data.
No data.
No data available yet.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
Sign in to view the affected projects.
Advisories
No advisories yet.
References
History
Mon, 21 Sep 2026 08:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we inflate incoming data, the filter does not control the resulting size, and create a buffer no matter what. Some compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size. The fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception. It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes) For application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize: public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted. Here are the additional constructor: public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize, final long maxDecompressRatio, final long decompressRatioMinSize) Also note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters: CompressionFilter compressionFilter = new CompressionFilter() .setCompressionLevel(Zlib.COMPRESSION_MAX) .setMaxDecompressedSize(1_000_000) .setMaxDecompressRatio(100). .setDecompressRatioMinSize(100_000); Applications using Apache MINA are advised to upgrade and configure their CompressionFilter instance. | |
| Title | Apache MINA: Unbounded Decompression Amplification DoS in Zlib.inflate | |
| Weaknesses | CWE-409 CWE-789 |
|
| References |
| |
| Metrics |
cvssV3_1
|
Subscriptions
No data.
MITRE
Status: PUBLISHED
Assigner: apache
Published:
Updated: 2026-09-21T07:43:24.769Z
Reserved: 2026-05-19T07:41:55.668Z
Link: CVE-2026-47321
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-21T08:16:37.520
Modified: 2026-09-21T08:16:37.520
Link: CVE-2026-47321
Redhat
No data.
OpenCVE Enrichment
No data.