CVE-2026-47321

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.
Configurations

No configuration.

History

21 Sep 2026, 19:17

Type Values Removed Values Added
References
  • () http://www.openwall.com/lists/oss-security/2026/09/21/1 -

21 Sep 2026, 08:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-09-21 08:16

Updated : 2026-09-21 19:17


NVD link : CVE-2026-47321

Mitre link : CVE-2026-47321

CVE.ORG link : CVE-2026-47321


JSON object : View

Products Affected

No product.

CWE
CWE-409

Improper Handling of Highly Compressed Data (Data Amplification)

CWE-789

Memory Allocation with Excessive Size Value