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Fencer Intel
medium 5.3

CVE-2025-6516 json

HDF5 H5Fint.c H5F_addr_decode_len heap-based overflow

published last yr. modified 3mo ago also EUVD-2025-18903 , JLSEC-2026-341

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

A vulnerability has been found in HDF5 up to 1.14.6 and classified as critical. This vulnerability affects the function H5F_addr_decode_len of the file /hdf5/src/H5Fint.c. The manipulation leads to heap-based buffer overflow. An attack has to be approached locally. The exploit has been disclosed to the public and may be used.

Patch / fix

  • julia HDF5_jll 2.0.0+0
  • hdf5 Debian 14 2.1.0+repack-1

debian advisories DEBIAN-CVE-2025-6516

  • hdf5 enterprise linux ai 3.0 1.14.6-6.el9ai
  • hdf5-openmpi enterprise linux ai 3.0 1.14.6-6.el9ai

red hat advisories RHSA-2025:23731

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-6516 updated cvss 5.3

hdf5: HDF5 heap-based overflow

  • Red Hat Enterprise Linux AI (RHEL AI) hdf5
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux AI 3.0 for RHEL 9 hdf5 1.14.6-6.el9ai, hdf5-openmpi 1.14.6-6.el9ai
    fixed: vendor fix RHSA-2025:23731

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/user-attachments/files/20626851/reproduce.tar.gz referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/HDFGroup/hdf5/issues/5581 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 4.8 CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
CNA 3.1 5.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R
CNA 3.0 5.3 CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R
CNA 2.0 4.3 AV:L/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:ND/RC:UR
CNA 4.0 1.9 CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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
CNA 3.1 5.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 2.0 4.3 AV:L/AC:L/Au:S/C:P/I:P/A:P
OSV 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
julia HDF5_jll
<2.0.0+0
2.0.0+0

Affected products

  • n/a HDF5

Classification

Weakness
  • CWE-122 Heap-based Buffer Overflow
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
  • CWE-787 Out-of-bounds Write

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.