CVE-2025-6856

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.21% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 11.3% of scored records. A rank, not a probability.

NVD base score

1.9 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/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

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

Low. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2025-06-29 09:31Z1 YR AGO

Last updated

2025-06-30 16:02Z1 YR AGO

Reserved

2025-06-28

Assigning CNA

VulDB

Record state

PUBLISHED

Severity

Medium (CVSS 4.8)

CNA CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

Weaknesses

• CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferClass
• CWE-416Use After FreeVariant
• CWE-911Improper Update of Reference CountBase

Data version

5.1

Document digest

9719f6bc0d415537263023a5a4f54b5b8c674e5ea9bb1a000c2b380a9d16e03d

• vuldb.comVDB-314328 | HDF5 H5FL.c H5FL__reg_gc_list use after freehttps://vuldb.com/?id.314328vdb-entrytechnical-description
• vuldb.comVDB-314328 | CTI Indicators (IOB, IOC, IOA)https://vuldb.com/?ctiid.314328signaturepermissions-required
• vuldb.comSubmit #602528 | HDFGroup HDF5 hdf5 1.14.6 (commit 17c16b6) Use After Freehttps://vuldb.com/?submit.602528third-party-advisory
• github.comhttps://github.com/HDFGroup/hdf5/issues/5574issue-tracking
• github.comhttps://github.com/user-attachments/files/20623417/hdf5_crash_6.txtexploit