FKIE_CVE-2026-68123
Vulnerability from fkie_nvd - Published: 2026-08-10 13:19 - Updated: 2026-08-19 17:20
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
openvswitch: fix GSO userspace truncation underflow
OVS_ACTION_ATTR_TRUNC currently stores a delta from the original skb
length in OVS_CB(skb)->cutlen. When a later userspace action segments a
GSO skb, queue_gso_packets() reuses that delta for each smaller segment.
A segment can then reach queue_userspace_packet() with cutlen greater
than skb->len, underflowing the length passed to skb_zerocopy().
Store the maximum preserved length instead and bound each consumer
against the current skb length. Use U32_MAX as the no-truncation
sentinel so the value remains valid if skb geometry changes before a
consumer handles it.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/openvswitch/actions.c",
"net/openvswitch/datapath.c",
"net/openvswitch/datapath.h",
"net/openvswitch/vport.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "50a6a85f3d6b1d22d8436848606cdef5d2c490b4",
"status": "affected",
"version": "f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1",
"versionType": "git"
},
{
"lessThan": "2623c48cc3a8da9a1886fd8f65c0e348f4406fd6",
"status": "affected",
"version": "f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1",
"versionType": "git"
},
{
"lessThan": "e211b081901ffca76674082c73eeaed53524c369",
"status": "affected",
"version": "f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1",
"versionType": "git"
},
{
"lessThan": "a16eaaf7c0b0ccdef6166707d90ffbc6eebf6855",
"status": "affected",
"version": "f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1",
"versionType": "git"
},
{
"lessThan": "fbfa3ad2ad6f3a5624aba5211c46290fb98cc9dc",
"status": "affected",
"version": "f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1",
"versionType": "git"
},
{
"lessThan": "100a23b1613e9218e0af654ef102352c713f0263",
"status": "affected",
"version": "f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1",
"versionType": "git"
},
{
"lessThan": "ea85dbcbe8d4056ecb54352f97743d138ea4c407",
"status": "affected",
"version": "f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1",
"versionType": "git"
},
{
"lessThan": "4032f8ed10fcb84d41c508dfb04be96589f78dfe",
"status": "affected",
"version": "f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/openvswitch/actions.c",
"net/openvswitch/datapath.c",
"net/openvswitch/datapath.h",
"net/openvswitch/vport.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.8"
},
{
"lessThan": "4.8",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.148",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.101",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.42",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nopenvswitch: fix GSO userspace truncation underflow\n\nOVS_ACTION_ATTR_TRUNC currently stores a delta from the original skb\nlength in OVS_CB(skb)-\u003ecutlen. When a later userspace action segments a\nGSO skb, queue_gso_packets() reuses that delta for each smaller segment.\nA segment can then reach queue_userspace_packet() with cutlen greater\nthan skb-\u003elen, underflowing the length passed to skb_zerocopy().\n\nStore the maximum preserved length instead and bound each consumer\nagainst the current skb length. Use U32_MAX as the no-truncation\nsentinel so the value remains valid if skb geometry changes before a\nconsumer handles it."
}
],
"id": "CVE-2026-68123",
"lastModified": "2026-08-19T17:20:29.700",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-08-10T13:19:57.427",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/100a23b1613e9218e0af654ef102352c713f0263"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2623c48cc3a8da9a1886fd8f65c0e348f4406fd6"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4032f8ed10fcb84d41c508dfb04be96589f78dfe"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/50a6a85f3d6b1d22d8436848606cdef5d2c490b4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a16eaaf7c0b0ccdef6166707d90ffbc6eebf6855"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e211b081901ffca76674082c73eeaed53524c369"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ea85dbcbe8d4056ecb54352f97743d138ea4c407"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/fbfa3ad2ad6f3a5624aba5211c46290fb98cc9dc"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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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.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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