CVE-2026-46193: xfrm: ah: account for ESN high bits in async callbacks
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 0555d4f526232b3c9e3afbcd490c0c0793aefec6, 1dae77078ceb4bab833f7a4935f05c5b8c97b9ba, 2ffaa7a94f9a4d22724364a1821735a0231d9f8d; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.141.1-1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 0555d4f526232b3c9e3afbcd490c0c0793aefec6, 1dae77078ceb4bab833f7a4935f05c5b8c97b9ba, 2ffaa7a94f9a4d22724364a1821735a0231d9f8d; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.141.1-1 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: ah: account for ESN high bits in async callbacks AH allocates its temporary auth/ICV layout differently when ESN is enabled: the async ahash setup appends a 4-byte seqhi slot before the ICV or auth_data area, but the async completion callbacks still reconstruct the temporary layout as if seqhi were absent. With an async AH implementation selected, that makes AH copy or compare the wrong bytes on both the IPv4 and IPv6 paths. In UML repro on IPv4 AH with ESN and forced async hmac(sha1), ping fails with 100% packet loss, and the callback logs show the pre-fix drift: ah4 output_done: esn=1 err=0 icv_off=20 expected_off=24 ah4 input_done: esn=1 auth_off=20 expected_auth_off=24 icv_off=32 expected_icv_off=36 Reconstruct the callback-side layout the same way the setup path built it by skipping the ESN seqhi slot before locating the saved auth_data or ICV. Per RFC 4302, the ESN high-order 32 bits participate in the AH ICV computation, so the async callbacks must account for the seqhi slot. Post-fix, the same IPv4 AH+ESN+forced-async-hmac(sha1) UML repro shows the corrected offset (ah4 output_done: esn=1 err=0 icv_off=24 expected_off=24) and ping succeeds; net/ipv4/ah4.o and net/ipv6/ah6.o build clean at W=1. IPv6 AH+ESN was not exercised at runtime, and the change has not been tested against a real async hardware AH engine.
- Published
- May 28, 2026
- Updated
- Nov 6, 2026
- EPSS
- 0.1% · 3th percentile
- CWE
- —
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%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
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 kernel3.15 and later · before 6.6.140
- linux linux kernel6.7 and later · before 6.12.88
- linux linux kernel6.13 and later · before 6.18.30
- linux linux kernel6.19 and later · before 7.0.7
- linux linux kernel7.1
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
- 3.15affected
- d4d573d0334d07341beffdcf97e2b85d3955d8ae and later · before ec406c26c97594124e79d14516b729a8d5dced62affected · git
- d4d573d0334d07341beffdcf97e2b85d3955d8ae and later · before 1dae77078ceb4bab833f7a4935f05c5b8c97b9baaffected · git
- d4d573d0334d07341beffdcf97e2b85d3955d8ae and later · before 0555d4f526232b3c9e3afbcd490c0c0793aefec6affected · git
- d4d573d0334d07341beffdcf97e2b85d3955d8ae and later · before 729899a2aa8bda7844be0cdcd3b470f11b912edaaffected · git
- d4d573d0334d07341beffdcf97e2b85d3955d8ae and later · before 7db99a09b3bc87268287bc7ab5f2e7f382b5ad87affected · git
- d4d573d0334d07341beffdcf97e2b85d3955d8ae and later · before 2ffaa7a94f9a4d22724364a1821735a0231d9f8daffected · git
- d4d573d0334d07341beffdcf97e2b85d3955d8ae and later · before ec54093e6a8f87e800bb6aa15eb7fc1e33faa524affected · git
- before 3.15not affected · semver
- 5.15.210 and later · up to and including 5.15.*not 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 6.12.88-1 | 6.12.88-1 |
| Debian:14 | linux | before 7.0.7-1 | 7.0.7-1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-64kb | before 5.14.21-150400.24.235.1 | 5.14.21-150400.24.235.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-docs | before 5.14.21-150400.24.235.1 | 5.14.21-150400.24.235.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-obs-build | before 5.14.21-150400.24.235.1 | 5.14.21-150400.24.235.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-syms | before 5.14.21-150400.24.235.1 | 5.14.21-150400.24.235.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_58 | before 1-150400.9.7.1 | 1-150400.9.7.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-default | before 5.14.21-150400.24.235.1 | 5.14.21-150400.24.235.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-default-base | before 5.14.21-150400.24.235.1.150400.24.118.3 | 5.14.21-150400.24.235.1.150400.24.118.3 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-rt | before 5.14.21-150400.15.181.1 | 5.14.21-150400.15.181.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-source | before 5.14.21-150400.24.235.1 | 5.14.21-150400.24.235.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-source-rt | before 5.14.21-150400.15.181.1 | 5.14.21-150400.15.181.1 |
| SUSE:Linux Enterprise Server 15 SP4-LTSS | kernel-zfcpdump | before 5.14.21-150400.24.235.1 | 5.14.21-150400.24.235.1 |
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-2026-46190May 28, 2026 · mtd: spi-nor: debugfs: fix out-of-bounds read in spi_nor_params_show()28Monitor
- ← EarlierCVE-2026-46191May 28, 2026 · fbcon: Avoid OOB font access if console rotation fails28Monitor
- Later →CVE-2026-46195May 28, 2026 · smb: client: validate dacloffset before building DACL pointers39Monitor
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 | 0555d4f526232b3c9e3afbcd490c0c0793aefec6 | Vendor (CNA) |
| Linux Linux | 1dae77078ceb4bab833f7a4935f05c5b8c97b9ba | Vendor (CNA) |
| Linux Linux | 2ffaa7a94f9a4d22724364a1821735a0231d9f8d | Vendor (CNA) |
| Linux Linux | 729899a2aa8bda7844be0cdcd3b470f11b912eda | Vendor (CNA) |
| Linux Linux | 7db99a09b3bc87268287bc7ab5f2e7f382b5ad87 | Vendor (CNA) |
| Linux Linux | ec406c26c97594124e79d14516b729a8d5dced62 | Vendor (CNA) |
| Linux Linux | ec54093e6a8f87e800bb6aa15eb7fc1e33faa524 | Vendor (CNA) |
| azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 | 6.6.141.1-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| debian:linux | 6.1.176-1 · Debian:12 | Package registry (OSV) |
| suse:kernel-64kb | 5.14.21-150400.24.235.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-default | 5.14.21-150400.24.235.1 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-default-base | 5.14.21-150400.24.235.1.150400.24.118.3 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-docs | 5.14.21-150400.24.235.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-livepatch-SLE15-SP4_Update_58 | 1-150400.9.7.1 · SUSE:Linux Enterprise Live Patching 15 SP4 | Package registry (OSV) |
| suse:kernel-obs-build | 5.14.21-150400.24.235.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-rt | 5.14.21-150400.15.181.1 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-source | 5.14.21-150400.24.235.1 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-source-rt | 5.14.21-150400.15.181.1 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-syms | 5.14.21-150400.24.235.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-zfcpdump | 5.14.21-150400.24.235.1 · SUSE:Linux Enterprise Server 15 SP4-LTSS | 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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0290 · Jun 2, 2026(Linux Kernel Güvenlik Bildirimi)
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)
—
CVSS 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
- SSVC exploitation— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (9 more)Show less
- git.kernel.org/stable/c/1dae77078ceb4bab833f7a4935f05c5b8c97b9ba
- git.kernel.org/stable/c/2ffaa7a94f9a4d22724364a1821735a0231d9f8d
- git.kernel.org/stable/c/729899a2aa8bda7844be0cdcd3b470f11b912eda
- git.kernel.org/stable/c/7db99a09b3bc87268287bc7ab5f2e7f382b5ad87
- git.kernel.org/stable/c/ec406c26c97594124e79d14516b729a8d5dced62
- git.kernel.org/stable/c/ec54093e6a8f87e800bb6aa15eb7fc1e33faa524
- 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.