Microsoft · Heap Buffer Over-read via Non-Terminated Link Data in H5L__extern_traverse
Affects MicrosoftSource GCVE Database
Not known to be exploited · CVSS 6.9 Medium : upgrade to 2.3.0 when convenient.
Data as of 5 Nov 2026, 09:07 UTC
Thin evidence
One scorer or none| CNA (HDFG) | CVSS 4.0 | 6.9 |
|---|
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.3.0
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Upgrade HDF5 and hdfgroup/hdf5 to 2.3.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| The HDF GroupHDF5 | Affected
| Fixed in
|
GitHubhdfgroup/hdf5pkg:github/hdfgroup/hdf5Other threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
CVE-2026-120757 is a heap buffer over-read vulnerability in Microsoft products related to the H5L__extern_traverse function. The flaw involves non-terminated link data leading to out-of-bounds memory reads. No CVSS score or detailed impact information is provided.