CVE-2026-43089: xfrm_user: fix info leak in build_mapping()
Noroxi assessment
Priority: Monitor (action score 22/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.13% (FIRST EPSS).
- 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 1beb76b2053b68c491b78370794b8ff63c8f8c02, 521385cbd50ca9474396d88462fcdfa6489685d9, 5a1a4b049ddde41466ccac0daeec326254b133f2.
Low priority for now. Upgrade to Linux Linux 1beb76b2053b68c491b78370794b8ff63c8f8c02, 521385cbd50ca9474396d88462fcdfa6489685d9, 5a1a4b049ddde41466ccac0daeec326254b133f2 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_user: fix info leak in build_mapping() struct xfrm_usersa_id has a one-byte padding hole after the proto field, which ends up never getting set to zero before copying out to userspace. Fix that up by zeroing out the whole structure before setting individual variables.
- Published
- May 6, 2026
- Updated
- Oct 15, 2026
- EPSS
- 0.1% · 2th percentile
- CWE
- CWE-401
Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi 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 |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel2.6.29.1 and later · before 6.6.136
- linux linux kernel6.7 and later · before 6.12.83
- linux linux kernel6.13 and later · before 6.18.24
- linux linux kernel6.19 and later · before 6.19.14
- linux linux kernel7.0
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
- 2.6.29affected
- 3a2dfbe8acb154905fdc2fd03ec56df42e6c4cc4 and later · before 521385cbd50ca9474396d88462fcdfa6489685d9affected · git
- 3a2dfbe8acb154905fdc2fd03ec56df42e6c4cc4 and later · before c2779ae9a3e5a044e5ccd564681511bbbcc5fc0faffected · git
- 3a2dfbe8acb154905fdc2fd03ec56df42e6c4cc4 and later · before 72a8de41c3eb4dcf22bf3b674ea38fb2f75d6f32affected · git
- 3a2dfbe8acb154905fdc2fd03ec56df42e6c4cc4 and later · before d3125c541a96fb3c0fc7210112684baf22b6c24daffected · git
- 3a2dfbe8acb154905fdc2fd03ec56df42e6c4cc4 and later · before 5a1a4b049ddde41466ccac0daeec326254b133f2affected · git
- 3a2dfbe8acb154905fdc2fd03ec56df42e6c4cc4 and later · before f779a6b6cdb6e12baa0663063ac59ab2a8f20c0caffected · git
- 3a2dfbe8acb154905fdc2fd03ec56df42e6c4cc4 and later · before 700c9622b23c33b5933e6dcea816492c064e4e10affected · git
- 3a2dfbe8acb154905fdc2fd03ec56df42e6c4cc4 and later · before 1beb76b2053b68c491b78370794b8ff63c8f8c02affected · git
- before 2.6.29not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.176-1 | 6.1.176-1 |
| Debian:13 | linux | before 6.12.85-1 | 6.12.85-1 |
| Debian:14 | linux | before 6.19.14-1 | 6.19.14-1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kernel-default | before 4.12.14-122.320.1 | 4.12.14-122.320.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_85 | before 1-8.3.1 | 1-8.3.1 |
| SUSE:Linux Enterprise Server 12 SP5-LTSS | kernel-source | before 4.12.14-122.320.1 | 4.12.14-122.320.1 |
| SUSE:Linux Enterprise Server 12 SP5-LTSS | kernel-syms | before 4.12.14-122.320.1 | 4.12.14-122.320.1 |
| SUSE:Linux Micro 6.0 | kernel-default | before 6.4.0-49.1 | 6.4.0-49.1 |
| SUSE:Linux Micro 6.0 | kernel-kvmsmall | before 6.4.0-49.1 | 6.4.0-49.1 |
| SUSE:Linux Micro 6.0 | kernel-rt | before 6.4.0-49.1 | 6.4.0-49.1 |
| SUSE:Linux Micro 6.0 | kernel-source | before 6.4.0-49.1 | 6.4.0-49.1 |
| SUSE:Linux Micro 6.0 | kernel-source-rt | before 6.4.0-49.1 | 6.4.0-49.1 |
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-2026-43084May 6, 2026 · netfilter: nfnetlink_queue: make hash table per queue31Monitor
- ← EarlierCVE-2026-43085May 6, 2026 · netfilter: nfnetlink_log: initialize nfgenmsg in NLMSG_DONE terminator22Monitor
- Later →CVE-2026-43091May 6, 2026 · xfrm: Wait for RCU readers during policy netns exit31Monitor
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 | 1beb76b2053b68c491b78370794b8ff63c8f8c02 | Vendor (CNA) |
| Linux Linux | 521385cbd50ca9474396d88462fcdfa6489685d9 | Vendor (CNA) |
| Linux Linux | 5a1a4b049ddde41466ccac0daeec326254b133f2 | Vendor (CNA) |
| Linux Linux | 700c9622b23c33b5933e6dcea816492c064e4e10 | Vendor (CNA) |
| Linux Linux | 72a8de41c3eb4dcf22bf3b674ea38fb2f75d6f32 | Vendor (CNA) |
| Linux Linux | c2779ae9a3e5a044e5ccd564681511bbbcc5fc0f | Vendor (CNA) |
| Linux Linux | d3125c541a96fb3c0fc7210112684baf22b6c24d | Vendor (CNA) |
| Linux Linux | f779a6b6cdb6e12baa0663063ac59ab2a8f20c0c | Vendor (CNA) |
| debian:linux | 6.1.176-1 · Debian:12 | Package registry (OSV) |
| suse:kernel-default | 6.4.0-49.1 · SUSE:Linux Micro 6.0 | Package registry (OSV) |
| suse:kernel-kvmsmall | 6.4.0-49.1 · SUSE:Linux Micro 6.0 | Package registry (OSV) |
| suse:kernel-rt | 6.4.0-49.1 · SUSE:Linux Micro 6.0 | Package registry (OSV) |
| suse:kernel-source | 6.4.0-49.1 · SUSE:Linux Micro 6.0 | Package registry (OSV) |
| suse:kernel-source-rt | 6.4.0-49.1 · SUSE:Linux Micro 6.0 | Package registry (OSV) |
| suse:kernel-syms | 4.12.14-122.320.1 · SUSE:Linux Enterprise Server 12 SP5-LTSS | Package registry (OSV) |
| suse:kgraft-patch-SLE12-SP5_Update_85 | 1-8.3.1 · SUSE:Linux Enterprise Live Patching 12 SP5 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
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.
No dated events beyond publication.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
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
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-401 · Missing Release of Memory after Effective LifetimeCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
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
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (10 more)Show less
- git.kernel.org/stable/c/521385cbd50ca9474396d88462fcdfa6489685d9
- git.kernel.org/stable/c/5a1a4b049ddde41466ccac0daeec326254b133f2
- git.kernel.org/stable/c/700c9622b23c33b5933e6dcea816492c064e4e10
- git.kernel.org/stable/c/72a8de41c3eb4dcf22bf3b674ea38fb2f75d6f32
- git.kernel.org/stable/c/c2779ae9a3e5a044e5ccd564681511bbbcc5fc0f
- git.kernel.org/stable/c/d3125c541a96fb3c0fc7210112684baf22b6c24d
- git.kernel.org/stable/c/f779a6b6cdb6e12baa0663063ac59ab2a8f20c0c
- cert-portal.siemens.com/productcert/html/ssa-019113.html
- cert-portal.siemens.com/productcert/html/ssa-457936.html
- cert-portal.siemens.com/productcert/html/ssa-784472.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.