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NVD / CVE Program· CNA Linux

CVE-2026-80843: xfrm: fix xfrm_state_construct() auth-trunc leak

Noroxi assessment

Priority: Monitor (action score 0/100)

  • 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: 0.19% (FIRST EPSS).
  • Fixed version: Linux Linux 37426395cb90ef217beec8407a14bd82153793d3, 71d42da01740ec6557837bebec0bc48cfc3b4c39, 958ae9f261319e1cdc44879886bcda2263258cca; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.

Low priority for now. Upgrade to Linux Linux 37426395cb90ef217beec8407a14bd82153793d3, 71d42da01740ec6557837bebec0bc48cfc3b4c39, 958ae9f261319e1cdc44879886bcda2263258cca; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 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: fix xfrm_state_construct() auth-trunc leak attach_auth_trunc() can allocate x->aalg while leaving x->props.aalgo at zero when the selected auth algorithm has no sadb_alg_id. One real case is cmac(aes). xfrm_state_construct() then treats !x->props.aalgo as "no auth algorithm attached yet" and calls attach_auth(). That overwrites x->aalg and loses the first allocation. Any later failure or teardown only frees the replacement pointer. Check whether x->aalg is already attached instead of inferring that state from x->props.aalgo.

—No exploit Fix available
Published
Sep 4, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 9th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
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

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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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.

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Affected 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.

—

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

    • 2.6.33affected
    • 4447bb33f09444920a8f1d89e1540137429351b6 and later · before 958ae9f261319e1cdc44879886bcda2263258ccaaffected · git
    • 4447bb33f09444920a8f1d89e1540137429351b6 and later · before fb7f3e74789a3c89647f4eb768f6dfaf4a751e72affected · git
    • 4447bb33f09444920a8f1d89e1540137429351b6 and later · before ba0c110c205855b3f1e3130d8c0fdb484d704c8caffected · git
    • 4447bb33f09444920a8f1d89e1540137429351b6 and later · before c8837bbe792257af547fd1c0252553ce13148795affected · git
    • 4447bb33f09444920a8f1d89e1540137429351b6 and later · before 71d42da01740ec6557837bebec0bc48cfc3b4c39affected · git
    • 4447bb33f09444920a8f1d89e1540137429351b6 and later · before cf67361e78dca488d6e4df8396a53e6745a3a80eaffected · git
    • 4447bb33f09444920a8f1d89e1540137429351b6 and later · before 37426395cb90ef217beec8407a14bd82153793d3affected · git
    • 4447bb33f09444920a8f1d89e1540137429351b6 and later · before be19d20e53a239572bb2a28efcc1cd2b069b1ef9affected · git
    • 4447bb33f09444920a8f1d89e1540137429351b6 and later · before c12cbf56320fb633484ee0ca1fb7d68d6b64b213affected · git

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.187-16.1.187-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.1.13-17.1.13-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-80841Sep 4, 2026 · net/packet: defer vmalloc TX_RING free until skbs finish
    0Monitor
  • ← EarlierCVE-2026-80842Sep 4, 2026 · net: bridge: mcast: fix use-after-free of a master VLAN's multicast context
    0Monitor
  • Later →CVE-2026-80844Sep 4, 2026 · xfrm: ah6: validate routing header segments_left
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux37426395cb90ef217beec8407a14bd82153793d3Vendor (CNA)
Linux Linux71d42da01740ec6557837bebec0bc48cfc3b4c39Vendor (CNA)
Linux Linux958ae9f261319e1cdc44879886bcda2263258ccaVendor (CNA)
Linux Linuxba0c110c205855b3f1e3130d8c0fdb484d704c8cVendor (CNA)
Linux Linuxbe19d20e53a239572bb2a28efcc1cd2b069b1ef9Vendor (CNA)
Linux Linuxc12cbf56320fb633484ee0ca1fb7d68d6b64b213Vendor (CNA)
Linux Linuxc8837bbe792257af547fd1c0252553ce13148795Vendor (CNA)
Linux Linuxcf67361e78dca488d6e4df8396a53e6745a3a80eVendor (CNA)
Linux Linuxfb7f3e74789a3c89647f4eb768f6dfaf4a751e72Vendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0—Microsoft (MSRC)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.06.6.157.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.1.187-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package 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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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 researchers

Finders, 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

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

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✗ → ✓

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References

Show all references (8 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records