CVE-2026-26197 (GCVE-0-2026-26197)
Vulnerability from cvelistv5 – Published: 2026-07-20 14:55 – Updated: 2026-07-20 15:34
VLAI
EPSS
VEX
Title
Array full size, element count, and element size are not checked to make sure they match in H5Odtype.c
Summary
HDF5 is a high-performance library and a file format specification that implements the HDF5 data model. If a file is corrupted such that an array datatype's size, the number of elements, and the element size are not in agreement it can trigger an out of bounds read. The array datatype stores the full size of the datatype (`dt->shared->size`) separately from the number of elements (`dt->shared->u.array.nelem`) and the element size (`dt->shared->parent->shared->size`). If any one of these are corrupted so that they don't align with the others (element size * nelem = full size), it can lead to an out of bounds read. Depending on what is corrupted, it can alter the type of out of bounds read triggered. The vulnerability is present only in files that have been maliciously altered, as its generally not possible to independently alter the full size of the datatype, the element count and the element size. As such, this is only present if a malicious actor is altering files, and won't appear in regular usage.
Severity
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-125 - Out-of-bounds Read
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/HDFGroup/hdf5/security/advisor… | x_refsource_CONFIRM |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-26197",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-20T15:32:48.424585Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-07-20T15:34:11.301Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"exploit"
],
"url": "https://github.com/HDFGroup/hdf5/security/advisories/GHSA-gh44-7wpq-622f"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "hdf5",
"vendor": "HDFGroup",
"versions": [
{
"status": "affected",
"version": "\u003c 2.0.0"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "HDF5 is a high-performance library and a file format specification that implements the HDF5 data model. If a file is corrupted such that an array datatype\u0027s size, the number of elements, and the element size are not in agreement it can trigger an out of bounds read. The array datatype stores the full size of the datatype (`dt-\u003eshared-\u003esize`) separately from the number of elements (`dt-\u003eshared-\u003eu.array.nelem`) and the element size (`dt-\u003eshared-\u003eparent-\u003eshared-\u003esize`). If any one of these are corrupted so that they don\u0027t align with the others (element size * nelem = full size), it can lead to an out of bounds read. Depending on what is corrupted, it can alter the type of out of bounds read triggered. The vulnerability is present only in files that have been maliciously altered, as its generally not possible to independently alter the full size of the datatype, the element count and the element size. As such, this is only present if a malicious actor is altering files, and won\u0027t appear in regular usage."
}
],
"metrics": [
{
"cvssV4_0": {
"attackComplexity": "HIGH",
"attackRequirements": "PRESENT",
"attackVector": "NETWORK",
"baseScore": 5.9,
"baseSeverity": "MEDIUM",
"privilegesRequired": "NONE",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "ACTIVE",
"vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-125",
"description": "CWE-125: Out-of-bounds Read",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-07-20T14:55:50.636Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/HDFGroup/hdf5/security/advisories/GHSA-gh44-7wpq-622f",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/HDFGroup/hdf5/security/advisories/GHSA-gh44-7wpq-622f"
}
],
"source": {
"advisory": "GHSA-gh44-7wpq-622f",
"discovery": "UNKNOWN"
},
"title": "Array full size, element count, and element size are not checked to make sure they match in H5Odtype.c"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-26197",
"datePublished": "2026-07-20T14:55:50.636Z",
"dateReserved": "2026-02-11T19:56:24.813Z",
"dateUpdated": "2026-07-20T15:34:11.301Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-26197",
"date": "2026-07-22",
"epss": "0.00256",
"percentile": "0.17175"
},
"microsoft_vex": {
"current_release_date": "2026-07-22T01:01:19.000Z",
"cve": "CVE-2026-26197",
"id": "msrc_CVE-2026-26197",
"initial_release_date": "2026-07-22T01:01:19.000Z",
"product_status:known_affected": "1",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "Array full size, element count, and element size are not checked to make sure they match in H5Odtype.c",
"url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-26197.json",
"version": "1"
},
"nvd": "{\"cve\":{\"id\":\"CVE-2026-26197\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-07-20T16:16:57.400\",\"lastModified\":\"2026-07-20T16:16:57.400\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"HDF5 is a high-performance library and a file format specification that implements the HDF5 data model. If a file is corrupted such that an array datatype\u0027s size, the number of elements, and the element size are not in agreement it can trigger an out of bounds read. The array datatype stores the full size of the datatype (`dt-\u003eshared-\u003esize`) separately from the number of elements (`dt-\u003eshared-\u003eu.array.nelem`) and the element size (`dt-\u003eshared-\u003eparent-\u003eshared-\u003esize`). If any one of these are corrupted so that they don\u0027t align with the others (element size * nelem = full size), it can lead to an out of bounds read. Depending on what is corrupted, it can alter the type of out of bounds read triggered. The vulnerability is present only in files that have been maliciously altered, as its generally not possible to independently alter the full size of the datatype, the element count and the element size. As such, this is only present if a malicious actor is altering files, and won\u0027t appear in regular usage.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"HDFGroup\",\"product\":\"hdf5\",\"versions\":[{\"version\":\"\u003c 2.0.0\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/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\",\"baseScore\":5.9,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"attackRequirements\":\"PRESENT\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"ACTIVE\",\"vulnConfidentialityImpact\":\"NONE\",\"vulnIntegrityImpact\":\"NONE\",\"vulnAvailabilityImpact\":\"HIGH\",\"subConfidentialityImpact\":\"NONE\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-07-20T15:32:48.424585Z\",\"id\":\"CVE-2026-26197\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-125\"}]}],\"references\":[{\"url\":\"https://github.com/HDFGroup/hdf5/security/advisories/GHSA-gh44-7wpq-622f\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/HDFGroup/hdf5/security/advisories/GHSA-gh44-7wpq-622f\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\"}]}}",
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-07-21T06:22:53+00:00",
"cve": "CVE-2026-26197",
"id": "CVE-2026-26197",
"initial_release_date": "2026-07-20T14:55:50.636000+00:00",
"product_status:known_affected": "52",
"product_status:under_investigation": "1",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "hdf5: HDF5: Out-of-bounds read due to corrupted file can lead to denial of service",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26197.json",
"version": "3"
},
"vulnrichment": {
"containers": "{\"cna\": {\"title\": \"Array full size, element count, and element size are not checked to make sure they match in H5Odtype.c\", \"problemTypes\": [{\"descriptions\": [{\"cweId\": \"CWE-125\", \"lang\": \"en\", \"description\": \"CWE-125: Out-of-bounds Read\", \"type\": \"CWE\"}]}], \"metrics\": [{\"cvssV4_0\": {\"attackVector\": \"NETWORK\", \"attackComplexity\": \"HIGH\", \"attackRequirements\": \"PRESENT\", \"privilegesRequired\": \"NONE\", \"userInteraction\": \"ACTIVE\", \"vulnConfidentialityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"HIGH\", \"subConfidentialityImpact\": \"NONE\", \"subIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"NONE\", \"baseScore\": 5.9, \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N\", \"version\": \"4.0\"}}], \"references\": [{\"name\": \"https://github.com/HDFGroup/hdf5/security/advisories/GHSA-gh44-7wpq-622f\", \"tags\": [\"x_refsource_CONFIRM\"], \"url\": \"https://github.com/HDFGroup/hdf5/security/advisories/GHSA-gh44-7wpq-622f\"}], \"affected\": [{\"vendor\": \"HDFGroup\", \"product\": \"hdf5\", \"versions\": [{\"version\": \"\u003c 2.0.0\", \"status\": \"affected\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-07-20T14:55:50.636Z\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"HDF5 is a high-performance library and a file format specification that implements the HDF5 data model. If a file is corrupted such that an array datatype\u0027s size, the number of elements, and the element size are not in agreement it can trigger an out of bounds read. The array datatype stores the full size of the datatype (`dt-\u003eshared-\u003esize`) separately from the number of elements (`dt-\u003eshared-\u003eu.array.nelem`) and the element size (`dt-\u003eshared-\u003eparent-\u003eshared-\u003esize`). If any one of these are corrupted so that they don\u0027t align with the others (element size * nelem = full size), it can lead to an out of bounds read. Depending on what is corrupted, it can alter the type of out of bounds read triggered. The vulnerability is present only in files that have been maliciously altered, as its generally not possible to independently alter the full size of the datatype, the element count and the element size. As such, this is only present if a malicious actor is altering files, and won\u0027t appear in regular usage.\"}], \"source\": {\"advisory\": \"GHSA-gh44-7wpq-622f\", \"discovery\": \"UNKNOWN\"}}, \"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-26197\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-07-20T15:32:48.424585Z\"}}}], \"references\": [{\"url\": \"https://github.com/HDFGroup/hdf5/security/advisories/GHSA-gh44-7wpq-622f\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-07-20T15:34:04.810Z\"}}]}",
"cveMetadata": "{\"cveId\": \"CVE-2026-26197\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"state\": \"PUBLISHED\", \"assignerShortName\": \"GitHub_M\", \"dateReserved\": \"2026-02-11T19:56:24.813Z\", \"datePublished\": \"2026-07-20T14:55:50.636Z\", \"dateUpdated\": \"2026-07-20T15:34:11.301Z\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
Loading…