CVE Intelligence
High exploit reference

CVE-2026-43284 — xfrm: esp: avoid in-place decrypt on shared skb frags

In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: avoid in-place decrypt on shared skb frags MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(), so later paths that may modify packet data can first make a private copy. The IPv4/IPv6 datagram append paths did not set this flag when splicing pages into UDP skbs. That leaves an ESP-in-UDP packet made from shared pipe pages looking like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW fast path for uncloned skbs without a frag_list and decrypts in place over data that is not owned privately by the skb. Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching TCP. Also make ESP input fall back to skb_cow_data() when the flag is present, so ESP does not decrypt externally backed frags in place. Private nonlinear skb frags still use the existing fast path. This intentionally does not change ESP output. In esp_output_head(), the path that appends the ESP trailer to existing skb tailroom without calling skb_cow_data() is not reachable for nonlinear skbs: skb_tailroom() returns zero when skb->data_len is nonzero, while ESP tailen is positive. Thus ESP output will either use the separate destination-frag path or fall back to skb_cow_data().

Published May 8, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

Metasploit modules · 1Exploit-DB · 2
How the score was calculated
  • Public exploit/PoC (metasploit, exploitdb)+20
  • EPSS 2.5% (30-day exploitation probability)+13
  • Technical severity (high)+6
  • CISA SSVC: exploitation "poc"+5

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
2.47%
ahead of 84% of scored CVEs · Oct 15, 2026
Affects
Linux
Linux and 1 more
CVSS base
8.8
High · 5 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Proof of concept
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
  2. Apply the fixed version or the patch documented under Remediation.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux ≥ cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and < fe785bb3a8096dffcc4048a85cd0c83337eeecadversion 4.11≥ cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and < f4c50a4034e62ab75f1d5cdd191dd5f9c77fdff4≥ cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and < 52646cbd00e765a6db9c3afe9535f26218276034≥ cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and < 71a1d9d985d26716f74d21f18ee8cac821b06e97≥ cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and < b54edf1e9a3fd3491bdcb82a21f8d21315271e0d≥ cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and < 50ed1e7873100f77abad20fd31c51029bc49cd03≥ cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and < 8253aab4659ca16116b522203c2a6b18dccacea7
and 3 more ≥ cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and < 5d55c7336f8032d434adcc5fab987ccc93a44aec≥ cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and < ab8b995323e5237041472d07e5055f5f7dcdf15b≥ cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and < a6cb440f274a22456ef3e86b457344f1678f38f9
Vulnerable CVE Program (cve.org) e CISA ADP
Linux Linux Kernel ≥ 4.11 and < 5.10.255≥ 7.0 and < 7.0.5≥ 6.13 and < 6.18.28≥ 6.7 and < 6.12.87≥ 6.2 and < 6.6.138≥ 5.16 and < 6.1.171≥ 5.12 and < 5.15.205 Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
8.8 CVSS 3.1 High 2.0 6.0 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
8.8 CVSS 3.1 High — — Linux via CVE Program (cve.org) e CISA ADP
7.8 CVSS 3.1 High 1.1 6.0 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
7.8 CVSS 3.1 High 1.8 5.9 0b0ca135-0b70-47e7-9f44-1890c2a1c46c via NIST National Vulnerability Database
7.8 CVSS 3.1 High — — CISA-ADP via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)
Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 8.8 (416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-123

Other CVEs with this weakness →

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Metasploit modules
Exploit-DB

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 2.47%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · linux/linux
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 8.8
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVE published
    May 8, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

60 on the record

Elsewhere on this site

Linux
every CVE for this vendor
CWE-123
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-99999 ipv4: validate checksum_start before completing checksum 22h
  • CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 22h
  • CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
  • CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
  • CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
  • CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-43284 is "xfrm: esp: avoid in-place decrypt on shared skb frags", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. EPSS 2.47% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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