CVE-2026-63912 (GCVE-0-2026-63912)
Vulnerability from cvelistv5 – Published: 2026-07-19 14:55 – Updated: 2026-10-19 20:17
VLAI
EPSS
VEX
Title
xfrm: esp: restore combined single-frag length gate
Summary
In the Linux kernel, the following vulnerability has been resolved:
xfrm: esp: restore combined single-frag length gate
The ESP out-of-place fast path appends the trailer in esp_output_head()
before esp_output_tail() allocates the destination page frag. The
head-side gate currently checks skb->data_len and tailen separately, but
the tail code allocates a single destination frag from the combined
post-trailer skb->data_len.
Reject the page-frag fast path when the combined aligned length exceeds a
page. Otherwise skb_page_frag_refill() may fall back to a single page while
the destination sg still spans the combined skb->data_len.
Restore this combined-length page gate for both IPv4 and IPv6.
Severity
9.8 (Critical)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-16 15:33 UTC
CWE
- CWE-125 - Out-of-bounds Read
Assigner
References
8 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
c075c3ea031757f8ea2d34567565b61a868c08d5 , < 566295735530ee513326049b0540f32ec050bf2e
(git)
Affected: a583f2f3c8788bffd7fd7baeb76bd6d80543d7ea , < 5d7ab86e2b6bc23054616bf6ac562013bf60af8c (git) Affected: 5bd8baab087dff657e05387aee802e70304cc813 , < 36519e3d941fc99d3b52c134dbaf311f987a4708 (git) Affected: 5bd8baab087dff657e05387aee802e70304cc813 , < 322e48187e0245ab2fff6fec2220b0cae677dbec (git) Affected: 5bd8baab087dff657e05387aee802e70304cc813 , < b84091ceddc9f133229dceab3ccc930bf27f9cba (git) Affected: 5bd8baab087dff657e05387aee802e70304cc813 , < c093468aea8277f77272a4f199b2e15e19cabb59 (git) Affected: 5bd8baab087dff657e05387aee802e70304cc813 , < 65f3b3fc2347b89fe21db1e92c7681368415f095 (git) Affected: 5bd8baab087dff657e05387aee802e70304cc813 , < dfa0d7b0ff1eb6b2c416b8fdb9b4f2cefba57a40 (git) Affected: 2c66b0c95bb0aa7652ba1eba293d0d5993b35a38 (git) Affected: ef6f83df1209a7d9bd1c605a62457d4c00f9179e (git) Affected: 3defefd22ad5fbbe639b6157fb7e6311b2bf333d (git) Affected: b657030870bb5351c5b1e84d4e9f186da6ca0496 (git) Affected: 5.10.113 , < 5.10.259 (semver) Affected: 5.15.36 , < 5.15.210 (semver) Affected: 4.14.288 , < 4.15 (semver) Affected: 4.19.252 , < 4.20 (semver) Affected: 5.4.205 , < 5.5 (semver) Affected: 5.17.5 , < 5.18 (semver) |
guessed | |
| Linux | Linux |
Affected:
5.18
Unaffected: 0 , < 5.18 (semver) Unaffected: 5.10.259 , ≤ 5.10.* (semver) Unaffected: 5.15.210 , ≤ 5.15.* (semver) Unaffected: 6.1.176 , ≤ 6.1.* (semver) Unaffected: 6.6.143 , ≤ 6.6.* (semver) Unaffected: 6.12.93 , ≤ 6.12.* (semver) Unaffected: 6.18.35 , ≤ 6.18.* (semver) Unaffected: 7.0.12 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix) |
guessed |
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: esp: restore combined single-frag length gate\n\nThe ESP out-of-place fast path appends the trailer in esp_output_head()\nbefore esp_output_tail() allocates the destination page frag. The\nhead-side gate currently checks skb-\u003edata_len and tailen separately, but\nthe tail code allocates a single destination frag from the combined\npost-trailer skb-\u003edata_len.\n\nReject the page-frag fast path when the combined aligned length exceeds a\npage. Otherwise skb_page_frag_refill() may fall back to a single page while\nthe destination sg still spans the combined skb-\u003edata_len.\n\nRestore this combined-length page gate for both IPv4 and IPv6."
}
],
"id": "CVE-2026-63912",
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"source": "Red Hat CSAF VEX",
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"title": "kernel: xfrm: esp: restore combined single-frag length gate",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63912.json",
"version": "3"
},
"vulnrichment": {
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"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
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"title": "CISA ADP Vulnrichment"
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"cna": {
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}
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"dateUpdated": "2026-10-19T20:17:55.311Z",
"state": "PUBLISHED"
},
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}
}
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Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
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.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
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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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.