CVE-2026-43284: xfrm: esp: avoid in-place decrypt on shared skb frags
Noroxi assessment
Priority: This week (action score 63/100)
- A ready-made attack module is public (Metasploit); exploiting it takes no special expertise.
- Public proof-of-concept code exists (Exploit-DB, GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 94.1% (FIRST EPSS); higher than 99.8% of all records.
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Linux Linux 50ed1e7873100f77abad20fd31c51029bc49cd03, 52646cbd00e765a6db9c3afe9535f26218276034, 5d55c7336f8032d434adcc5fab987ccc93a44aec; azl3 kernel 6.6.137.1-2 on Azure Linux 3.0 6.6.138.1-1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Don’t wait for the next maintenance window. Upgrade to Linux Linux 50ed1e7873100f77abad20fd31c51029bc49cd03, 52646cbd00e765a6db9c3afe9535f26218276034, 5d55c7336f8032d434adcc5fab987ccc93a44aec; azl3 kernel 6.6.137.1-2 on Azure Linux 3.0 6.6.138.1-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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().
- BDU:2026-06439
- ALSA-2026:16195
- ALSA-2026:16196
- ALSA-2026:16206
- ALSA-2026:19074
- ALSA-2026:19225
- ALSA-2026:19568
- ALSA-2026:19569
- ALSA-2026:A004
- ALSA-2026:A005
- ALSA-2026:A006
- ALSA-2026:A007
- RHSA-2026:16061
- RHSA-2026:16062
- RHSA-2026:16100
- RHSA-2026:16195
- RHSA-2026:16196
- RHSA-2026:16201
- RHSA-2026:16202
- RHSA-2026:16203
- Published
- May 8, 2026
- Updated
- Nov 11, 2026
- EPSS
- 94.1% · 99th percentile
- CWE
- CWE-123
Report tools
Action score
63
Don’t wait for the next maintenance window.
- CVSS
- 35 / 40 · 8.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 28 / 30 · 94.1%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 8.8
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- Weaponized exploit exists
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 4.11affected
- cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and later · before a6cb440f274a22456ef3e86b457344f1678f38f9affected · git
- cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and later · before ab8b995323e5237041472d07e5055f5f7dcdf15baffected · git
- cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and later · before fe785bb3a8096dffcc4048a85cd0c83337eeecadaffected · git
- cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and later · before 5d55c7336f8032d434adcc5fab987ccc93a44aecaffected · git
- cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and later · before 8253aab4659ca16116b522203c2a6b18dccacea7affected · git
- cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and later · before 50ed1e7873100f77abad20fd31c51029bc49cd03affected · git
- cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and later · before b54edf1e9a3fd3491bdcb82a21f8d21315271e0daffected · git
- cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and later · before 71a1d9d985d26716f74d21f18ee8cac821b06e97affected · git
- cac2661c53f35cbe651bef9b07026a5a05ab8ce0 and later · before 52646cbd00e765a6db9c3afe9535f26218276034affected · git
Affected versions · NVD (7)
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel4.11 and later · before 5.10.255
- linux linux kernel5.12 and later · before 5.15.205
- linux linux kernel5.16 and later · before 6.1.171
- linux linux kernel6.2 and later · before 6.6.138
- linux linux kernel6.7 and later · before 6.12.87
- linux linux kernel6.13 and later · before 6.18.28
- linux linux kernel7.0 and later · before 7.0.5
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:10 | kernel | before 6.12.0-211.7.3.el10_2 | 6.12.0-211.7.3.el10_2 |
| AlmaLinux:10 | kernel | before 6.12.0-124.55.3.el10_1 | 6.12.0-124.55.3.el10_1 |
| AlmaLinux:10 | kernel | before 6.12.0-211.16.1.el10_2 | 6.12.0-211.16.1.el10_2 |
| AlmaLinux:10 | kernel-64k | before 6.12.0-124.55.3.el10_1 | 6.12.0-124.55.3.el10_1 |
| AlmaLinux:10 | kernel-64k | before 6.12.0-211.7.3.el10_2 | 6.12.0-211.7.3.el10_2 |
| AlmaLinux:10 | kernel-64k | before 6.12.0-211.16.1.el10_2 | 6.12.0-211.16.1.el10_2 |
| AlmaLinux:10 | kernel-64k-core | before 6.12.0-211.16.1.el10_2 | 6.12.0-211.16.1.el10_2 |
| AlmaLinux:10 | kernel-64k-core | before 6.12.0-124.55.3.el10_1 | 6.12.0-124.55.3.el10_1 |
| AlmaLinux:10 | kernel-64k-core | before 6.12.0-211.7.3.el10_2 | 6.12.0-211.7.3.el10_2 |
| AlmaLinux:10 | kernel-64k-debug | before 6.12.0-211.7.3.el10_2 | 6.12.0-211.7.3.el10_2 |
| AlmaLinux:10 | kernel-64k-debug | before 6.12.0-124.55.3.el10_1 | 6.12.0-124.55.3.el10_1 |
| AlmaLinux:10 | kernel-64k-debug | before 6.12.0-211.16.1.el10_2 | 6.12.0-211.16.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-core | before 6.12.0-211.7.3.el10_2 | 6.12.0-211.7.3.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-core | before 6.12.0-124.55.3.el10_1 | 6.12.0-124.55.3.el10_1 |
| AlmaLinux:10 | kernel-64k-debug-core | before 6.12.0-211.16.1.el10_2 | 6.12.0-211.16.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-devel | before 6.12.0-211.7.3.el10_2 | 6.12.0-211.7.3.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-devel | before 6.12.0-211.16.1.el10_2 | 6.12.0-211.16.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-devel | before 6.12.0-124.55.3.el10_1 | 6.12.0-124.55.3.el10_1 |
| AlmaLinux:10 | kernel-64k-debug-devel-matched | before 6.12.0-211.16.1.el10_2 | 6.12.0-211.16.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-devel-matched | before 6.12.0-124.55.3.el10_1 | 6.12.0-124.55.3.el10_1 |
| AlmaLinux:10 | kernel-64k-debug-devel-matched | before 6.12.0-211.7.3.el10_2 | 6.12.0-211.7.3.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-modules | before 6.12.0-211.7.3.el10_2 | 6.12.0-211.7.3.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-modules | before 6.12.0-211.16.1.el10_2 | 6.12.0-211.16.1.el10_2 |
| AlmaLinux:10 | kernel-64k-debug-modules | before 6.12.0-124.55.3.el10_1 | 6.12.0-124.55.3.el10_1 |
+96
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV90Now
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
Published before and after this one in the same product
- ← EarlierCVE-2026-43282May 6, 2026 · RDMA/ionic: Fix potential NULL pointer dereference in ionic_query_port22Monitor
- ← EarlierCVE-2026-43283May 6, 2026 · net: ethernet: ec_bhf: Fix dma_free_coherent() dma handle35Monitor
- Later →CVE-2025-71296May 8, 2026 · drm/tests: shmem: Hold reservation lock around purge22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 50ed1e7873100f77abad20fd31c51029bc49cd03 | Vendor (CNA) |
| Linux Linux | 52646cbd00e765a6db9c3afe9535f26218276034 | Vendor (CNA) |
| Linux Linux | 5d55c7336f8032d434adcc5fab987ccc93a44aec | Vendor (CNA) |
| Linux Linux | 71a1d9d985d26716f74d21f18ee8cac821b06e97 | Vendor (CNA) |
| Linux Linux | 8253aab4659ca16116b522203c2a6b18dccacea7 | Vendor (CNA) |
| Linux Linux | a6cb440f274a22456ef3e86b457344f1678f38f9 | Vendor (CNA) |
| Linux Linux | ab8b995323e5237041472d07e5055f5f7dcdf15b | Vendor (CNA) |
| Linux Linux | b54edf1e9a3fd3491bdcb82a21f8d21315271e0d | Vendor (CNA) |
| Linux Linux | f4c50a4034e62ab75f1d5cdd191dd5f9c77fdff4 | Vendor (CNA) |
| Linux Linux | fe785bb3a8096dffcc4048a85cd0c83337eeecad | Vendor (CNA) |
| azl3 kernel 6.6.137.1-2 on Azure Linux 3.0 | 6.6.138.1-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| almalinux:bpftool | 4.18.0-553.124.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel | 4.18.0-553.124.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-abi-stablelists | 4.18.0-553.124.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-core | 4.18.0-553.124.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-cross-headers | 4.18.0-553.124.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug | 4.18.0-553.124.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug-core | 4.18.0-553.124.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug-devel | 4.18.0-553.124.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug-modules | 4.18.0-553.124.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug-modules-extra | 4.18.0-553.124.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-devel | 4.18.0-553.124.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-doc | 4.18.0-553.124.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| debian:linux | 6.1.170-3 · Debian:12 | Package registry (OSV) |
| red hat:bpftool | 0:4.18.0-477.140.1.el8_8 · Red Hat:rhel_e4s:8.8::baseos | Package registry (OSV) |
| red hat:bpftool-debuginfo | 0:4.18.0-477.140.1.el8_8 · Red Hat:rhel_e4s:8.8::baseos | Package registry (OSV) |
| red hat:kernel | 0:4.18.0-477.140.1.el8_8 · Red Hat:rhel_e4s:8.8::baseos | Package registry (OSV) |
| red hat:kernel-abi-stablelists | 0:4.18.0-477.140.1.el8_8 · Red Hat:rhel_e4s:8.8::baseos | Package registry (OSV) |
| red hat:kernel-core | 0:4.18.0-477.140.1.el8_8 · Red Hat:rhel_e4s:8.8::baseos | Package registry (OSV) |
| red hat:kernel-debug | 0:4.18.0-477.140.1.el8_8 · Red Hat:rhel_e4s:8.8::baseos | Package registry (OSV) |
+17
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Metasploit module ×1
- Exploit-DB entry ×2
- Proof-of-concept repository on GitHub ×48
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | 48 repositories | 2026-05-08 → 2026-11-11 |
| Exploit-DB entry | local | 2026-05-29 |
| Exploit-DB entry | local | 2026-05-27 |
| Metasploit module | exploit/linux/local/cve_2026_43284_dirty_fragxfrm-ESP Page-Cache Write via CVE-2026-43284exploit | 2026-05-08 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- First PoCsame day
- Metasploitsame day
- Published
- TodayNov 13, 2026+189 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0213 · May 12, 2026(Linux Kernel Güvenlik Bildirimi)
Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-123 · Write-what-where ConditionCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- git.kernel.org/stable/c/52646cbd00e765a6db9c3afe9535f26218276034
- git.kernel.org/stable/c/5d55c7336f8032d434adcc5fab987ccc93a44aec
- git.kernel.org/stable/c/71a1d9d985d26716f74d21f18ee8cac821b06e97
- git.kernel.org/stable/c/8253aab4659ca16116b522203c2a6b18dccacea7
- git.kernel.org/stable/c/a6cb440f274a22456ef3e86b457344f1678f38f9
- git.kernel.org/stable/c/ab8b995323e5237041472d07e5055f5f7dcdf15b
- git.kernel.org/stable/c/b54edf1e9a3fd3491bdcb82a21f8d21315271e0d
- git.kernel.org/stable/c/f4c50a4034e62ab75f1d5cdd191dd5f9c77fdff4
- git.kernel.org/stable/c/fe785bb3a8096dffcc4048a85cd0c83337eeecad
- www.openwall.com/lists/oss-security/2026/05/08/7
- www.openwall.com/lists/oss-security/2026/05/13/6
- www.openwall.com/lists/oss-security/2026/05/14/2
- www.openwall.com/lists/oss-security/2026/05/14/4
- www.vicarius.io/vsociety/posts/cve-2026-43284-detection-script-dirty-frag-linux-kernel-local-privilege-escalation
- www.vicarius.io/vsociety/posts/cve-2026-43284-mitigation-script-dirty-frag-linux-kernel-local-privilege-escalation
- access.redhat.com/errata/RHSA-2026:16061
- access.redhat.com/errata/RHSA-2026:16062
- access.redhat.com/errata/RHSA-2026:16100
- access.redhat.com/errata/RHSA-2026:16155
Vendor advisories and official records. Exploit/PoC links are deliberately left out.