CVE-2026-17573: Double Free in H5D__chunk_copy() in HDF5 via a Crafted Chunk-Index Size Field
Vulnerability summary
CVE-2026-17573 is a medium (CVSS 5.5) Double Free vulnerability in hdfgroup hdf5. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 4.2% of scored vulnerabilities. 1 public exploit is recorded.
Not severe (CVSS 4, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 1Timeline
- 27-07-2026PublishedVulnerability first disclosed.
- 27-07-2026Last modifiedVulnerability information updated.
Description
A double free vulnerability was discovered in the HDF5 library. Processing a crafted HDF5 file containing an oversized chunk size field via h5repack may cause the application to abort due to a double free.
CVSS metrics
6 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated6.7MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:UDiffers
- NVDNIST4.0MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.15%
Chance of exploitation in the next 30 days
Percentile
4%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.15% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundHdf5
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- hdf5All versions (No fix recorded) | < 2.1.0+repack-1
Hdfgroup1 product
- hdf5< 2.2.0
The hdf group1 product
- hdf5≤ 2.1.1
Ubuntu1 product
- hdf5All versions (No fix recorded)
4 vendors · 4 products
