Medium
swtpm — security advisory
An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log.
- Products
- swtpm
- Affected versions
- 0.10.1+ds-1ubuntu2, 0.10.1+ds-1ubuntu3, 0.10.1+ds-1ubuntu4, 0.6.1-0ubuntu1, 0.6.1-0ubuntu2, 0.6.1-0ubuntu3, 0.6.1-0ubuntu4, 0.6.1-0ubuntu5, 0.6.3-0ubuntu1, 0.6.3-0ubuntu2, 0.6.3-0ubuntu3, 0.6.3-0ubuntu3.1, 0.6.3-0ubuntu3.2, 0.6.3-0ubuntu3.3, 0.7.3-0ubuntu2, 0.7.3-0ubuntu3, 0.7.3-0ubuntu5, 0.7.3-0ubuntu5.24.04.1, 0.7.3-0ubuntu8, 0.7.3-0ubuntu9
- Fixed versions
- Not specified
- CVEs
- CVE-2026-75900
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:17 UTC · Revision 1
Source evidence
An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log.
osv:UBUNTU-CVE-2026-75900
swtpm
Fixed versions: Not specified
swtpm
Fixed versions: Not specified
swtpm
Fixed versions: Not specified
swtpm
Fixed versions: Not specified
Complete source record
{
"id": "a8fee70bac6a2c30efb454b80913434dc26b6eb5fcaf007016dd27bd2b11be0b",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-75900",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-75900",
"summary": "An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log.",
"evidence": "osv:UBUNTU-CVE-2026-75900",
"products": [
{
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"value": "swtpm",
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"affected_versions": [
{
"value": "0.6.1-0ubuntu1",
"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
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{
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{
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{
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{
"name": {
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},
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"affected_versions": [
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{
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{
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},
"prerequisites": [],
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"affected_versions": [
{
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{
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"evidence": "/affected/3/versions"
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{
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"evidence": "/affected/3/versions"
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{
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}
],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2026-75900",
"aliases": [
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],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
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"events": [
{
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],
"package": {
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"purl": "pkg:deb/ubuntu/swtpm?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
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},
"versions": [
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"0.7.3-0ubuntu5",
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},
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"ecosystem": "Ubuntu:26.10"
},
"versions": [
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{
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},
{
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}
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}
],
"modified": "2026-10-17T13:01:05.908808941Z",
"provider": "osv",
"upstream": [
"CVE-2026-75900"
],
"references": [
"https://ubuntu.com/security/CVE-2026-75900",
"https://www.cve.org/CVERecord?id=CVE-2026-75900",
"https://github.com/stefanberger/swtpm/pull/1155",
"https://access.redhat.com/security/cve/CVE-2026-75900"
]
},
"related_cves": [
{
"value": "CVE-2026-75900",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 360965,
"published_at": "2026-08-19T08:17:00+00:00"
}