CVE-2026-74473 (GCVE-0-2026-74473)
Vulnerability from cvelistv5
Published
2026-08-15 12:27
Modified
2026-08-19 16:37
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
vxlan: use pskb_network_may_pull() in route_shortcircuit()
route_shortcircuit() currently calls pskb_may_pull(skb, sizeof(struct iphdr))
(or ipv6hdr), which checks if bytes are available starting from skb->data.
However, in vxlan_xmit(), skb->data points to the MAC header, so
skb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, 20)
only checks 20 bytes from skb->data (which is 14 bytes MAC header + 6 bytes of
IP header), leaving the rest of the IP header potentially un-pulled in non-linear
frags. Subsequent dereferences of ip_hdr(skb)->daddr can read beyond the pulled
linear buffer length.
Fix this by using pskb_network_may_pull(), which adds skb_network_offset(skb) to
the length check to ensure the full network header is present in the linear buffer.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: e4f67addf158f98f8197e08974966b18480dc751 Version: e4f67addf158f98f8197e08974966b18480dc751 Version: e4f67addf158f98f8197e08974966b18480dc751 Version: e4f67addf158f98f8197e08974966b18480dc751 Version: e4f67addf158f98f8197e08974966b18480dc751 Version: e4f67addf158f98f8197e08974966b18480dc751 Version: e4f67addf158f98f8197e08974966b18480dc751 Version: e4f67addf158f98f8197e08974966b18480dc751 |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/net/vxlan/vxlan_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "c419af4924c1593500a40519730ed98575d04a3e",
"status": "affected",
"version": "e4f67addf158f98f8197e08974966b18480dc751",
"versionType": "git"
},
{
"lessThan": "6bd0a3a1b5744166946f0c551a6665c3b46b05e4",
"status": "affected",
"version": "e4f67addf158f98f8197e08974966b18480dc751",
"versionType": "git"
},
{
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"status": "affected",
"version": "e4f67addf158f98f8197e08974966b18480dc751",
"versionType": "git"
},
{
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"status": "affected",
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"versionType": "git"
},
{
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"status": "affected",
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"versionType": "git"
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"versionType": "git"
},
{
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"versionType": "git"
},
{
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"status": "affected",
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"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/net/vxlan/vxlan_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.8"
},
{
"lessThan": "3.8",
"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": "6.6.151",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.103",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.265",
"versionStartIncluding": "3.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.216",
"versionStartIncluding": "3.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.183",
"versionStartIncluding": "3.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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"versionStartIncluding": "3.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.103",
"versionStartIncluding": "3.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.44",
"versionStartIncluding": "3.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.8",
"versionStartIncluding": "3.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "3.8",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: use pskb_network_may_pull() in route_shortcircuit()\n\nroute_shortcircuit() currently calls pskb_may_pull(skb, sizeof(struct iphdr))\n(or ipv6hdr), which checks if bytes are available starting from skb-\u003edata.\n\nHowever, in vxlan_xmit(), skb-\u003edata points to the MAC header, so\nskb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, 20)\nonly checks 20 bytes from skb-\u003edata (which is 14 bytes MAC header + 6 bytes of\nIP header), leaving the rest of the IP header potentially un-pulled in non-linear\nfrags. Subsequent dereferences of ip_hdr(skb)-\u003edaddr can read beyond the pulled\nlinear buffer length.\n\nFix this by using pskb_network_may_pull(), which adds skb_network_offset(skb) to\nthe length check to ensure the full network header is present in the linear buffer."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:N - route_shortcircuit() runs in vxlan_xmit() during overlay transmit; remote packets forwarded or routed onto a VXLAN netdev with route-short-circuit enabled reach this path without local access, matching net-stack guidance for network-reachable packet processing on cloud/SDN nodes.\nAC:L - An attacker can reliably craft non-linear skbs (scatter/gather/frags and size boundaries) and aim traffic at a known router MAC in the VXLAN FDB; no race or uncontrollable memory layout is required beyond targeting an RSC-enabled deployment, which is the scored scenario.\nPR:N - Exploitation needs no credentials or capabilities on the victim when VXLAN RSC is already configured; a remote peer only has to send IPv4/IPv6 frames that traverse the tunnel transmit path, with no netlink setup or CAP_NET_ADMIN in the target namespace.\nUI:N - Triggering the bug requires only attacker-controlled network traffic through the overlay; no victim mount, file open, link click, or other interactive action is needed.\nS:U - Impact is confined to the kernel hosting the VXLAN endpoint (memory disclosure, packet-header corruption, or crash); it does not cross VM, container, or IOMMU security boundaries by itself.\nC:H - The faulty pskb_may_pull() check leaves the IP/IPv6 header in non-linear frags, so ip_hdr(skb)-\u003edaddr/ipv6 daddr is read past the linear head and can disclose adjacent kernel memory per OOB-read guidance.\nI:H - The out-of-bounds destination address feeds neigh_lookup() and may rewrite eth_hdr()-\u003eh_dest before encapsulation, giving attacker-influenced overlay forwarding and a memory-safety primitive in the transmit path.\nA:H - Dereferencing network-header fields beyond the pulled linear buffer can provoke kernel oops/panic on affected skb layouts, and OOB reads in xmit context are treated as high availability impact even when exploitation is not fully weaponized."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-19T16:37:25.639Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/c419af4924c1593500a40519730ed98575d04a3e"
},
{
"url": "https://git.kernel.org/stable/c/6bd0a3a1b5744166946f0c551a6665c3b46b05e4"
},
{
"url": "https://git.kernel.org/stable/c/214ba43faf106cb06cd3dd30999c5c809c868b53"
},
{
"url": "https://git.kernel.org/stable/c/42887be7c4cf283cce02cd0fb6411221167c8b6c"
},
{
"url": "https://git.kernel.org/stable/c/aa0d31376d574ac858a40078431a77127bf04ee4"
},
{
"url": "https://git.kernel.org/stable/c/ee799977d7941dbfb11049e17edd9eaf4f8820f7"
},
{
"url": "https://git.kernel.org/stable/c/4f3f96e771a20263635bb5e1307c112d613b4bbd"
},
{
"url": "https://git.kernel.org/stable/c/26bb2dd0a8839617e2c79ffbbe1923f8e4bab9fb"
}
],
"title": "vxlan: use pskb_network_may_pull() in route_shortcircuit()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74473",
"datePublished": "2026-08-15T12:27:09.382Z",
"dateReserved": "2026-08-15T05:44:03.903Z",
"dateUpdated": "2026-08-19T16:37:25.639Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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