CVE-2026-120689: HDF5 through 2.2.0 contains an uncontrolled recursion vulnerability in H5B__iterate_helper() in
Affects hdf5Source GCVE Database
Not known to be exploited · CVSS 4.3 Medium.
Data as of 5 Nov 2026, 12:37 UTC
Thin evidence
One scorer or none| CNA (HDFG) | CVSS 4.0 | 4.3 |
|---|
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:UExploitation evidence
Disclosed: evidence found.
CVE published 2 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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10hdf5pkg:deb/ubuntu/hdf5?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTShdf5pkg:deb/ubuntu/hdf5?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTShdf5pkg:deb/ubuntu/hdf5?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTShdf5pkg:deb/ubuntu/hdf5?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu Pro 20.04 LTShdf5pkg:deb/ubuntu/hdf5?arch=source&distro=esm-apps/focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTShdf5pkg:deb/ubuntu/hdf5?arch=source&distro=esm-apps/bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, avoid opening untrusted or unverified HDF5 files to mitigate risk.
Description
HDF5 versions through 2.2.0 contain an uncontrolled recursion vulnerability in the H5B__iterate_helper() function. This flaw occurs when iterating a version 1 B-tree where a child node’s level is not properly verified, allowing crafted files with self-referential B-tree nodes to cause unbounded recursion. Triggering this vulnerability via certain API calls results in stack exhaustion and application crashes, leading to denial of service.