Bug 2565964

Summary: CVE-2026-120755 hdf5: hdf5: Denial of Service via out-of-bounds read in szip decompression [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Joel Chamberlain <jochambe>
Component: hdf5Assignee: Orion Poplawski <orion>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: epel10CC: igor.raits, orion, sagitterghostproton.me, scitech-bugs
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["2e08be46-bce6-4ce9-b025-3ecef358306d"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On:    
Bug Blocks: 2565912    

Description Joel Chamberlain 2026-11-03 17:00:32 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

HDF5 through 2.2.0 contains an out-of-bounds read vulnerability in H5Z__filter_szip() in src/H5Zszip.c. When decoding a szip-compressed chunk, the function subtracts the 4-byte uncompressed-length header from the chunk length without first verifying that the chunk is at least 4 bytes long. A truncated or corrupted chunk shorter than the header causes the length calculation to wrap around to a very large value, and the decompressor reads far past the end of the chunk buffer. An attacker who can get a user or application to read a dataset from a crafted HDF5 file can cause a denial of service. Only builds with szip support (libaec or the szip library) are affected.