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NVD / CVE Program· CNA Linux

CVE-2026-80844: xfrm: ah6: validate routing header segments_left

Noroxi assessment

Priority: Monitor (action score 0/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.43% (FIRST EPSS).
  • Fixed version: Linux Linux 0bf11081ad3753938a2b48723ce6298dbac743a1, 1516e31ac458a738be485620579d8f7fb2700fcb, 1b7e066eabcc7d6d8f476c34739b45932f2f4c31; 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 0bf11081ad3753938a2b48723ce6298dbac743a1, 1516e31ac458a738be485620579d8f7fb2700fcb, 1b7e066eabcc7d6d8f476c34739b45932f2f4c31; 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: ah6: validate routing header segments_left AH6 rearranges routing-header addresses before computing or verifying the ICV. ipv6_rearrange_rthdr() assumes that segments_left is not larger than the number of addresses described by the routing header's hdrlen field. That assumption does not hold for raw IPv6 HDRINCL packets. A packet with hdrlen equal to 2 describes one address, but can carry an arbitrary segments_left value. With segments_left equal to 255, the function moves its address pointer 4,064 bytes backwards and passes a 4,064-byte length to memmove(), resulting in an out-of-bounds access. Validate the invariant locally before modifying the routing header or performing any address-pointer arithmetic, and propagate malformed-header errors to the existing AH6 input and output error paths.

—Proof of concept Fix available
Published
Sep 4, 2026
Updated
Oct 19, 2026
EPSS
0.4% · 37th 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 · 0.4%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

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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

    • 2.6.12affected
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 2dc650956e4e163b879b3fb1027f9557abc5c985affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 48b0e36cf54358276ee7aa897034c973097d2bc9affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 1b7e066eabcc7d6d8f476c34739b45932f2f4c31affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before f00df8500e5a36ba70d336fd34bd2152ea074e5faffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 1516e31ac458a738be485620579d8f7fb2700fcbaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 6733ae71268a27d598cfb3f3339a3c950b9b656daffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 0bf11081ad3753938a2b48723ce6298dbac743a1affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 46640c814f25f096b0b0045ca50e1b7030cd8a30affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 7bad4bda74dc4713f398d3b7624ff05478e3a568affected · git

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-develbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-devel-matchedbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-docbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-headersbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-zfcpdump-develbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10kernel-zfcpdump-devel-matchedbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10perfbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:10python3-perfbefore 6.12.0-211.59.1.el10_26.12.0-211.59.1.el10_2
AlmaLinux:8bpftoolbefore 4.18.0-553.167.1.el8_104.18.0-553.167.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.167.1.el8_104.18.0-553.167.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.167.1.el8_104.18.0-553.167.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.167.1.el8_104.18.0-553.167.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.167.1.el8_104.18.0-553.167.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.167.1.el8_104.18.0-553.167.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.167.1.el8_104.18.0-553.167.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.167.1.el8_104.18.0-553.167.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.167.1.el8_104.18.0-553.167.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.167.1.el8_104.18.0-553.167.1.el8_10

+96

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-2026-80842Sep 4, 2026 · net: bridge: mcast: fix use-after-free of a master VLAN's multicast context
    0Monitor
  • ← EarlierCVE-2026-80843Sep 4, 2026 · xfrm: fix xfrm_state_construct() auth-trunc leak
    0Monitor
  • Later →CVE-2026-80845Sep 4, 2026 · xfrm: avoid lock inversion in nat keepalive work
    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 Linux0bf11081ad3753938a2b48723ce6298dbac743a1Vendor (CNA)
Linux Linux1516e31ac458a738be485620579d8f7fb2700fcbVendor (CNA)
Linux Linux1b7e066eabcc7d6d8f476c34739b45932f2f4c31Vendor (CNA)
Linux Linux2dc650956e4e163b879b3fb1027f9557abc5c985Vendor (CNA)
Linux Linux46640c814f25f096b0b0045ca50e1b7030cd8a30Vendor (CNA)
Linux Linux48b0e36cf54358276ee7aa897034c973097d2bc9Vendor (CNA)
Linux Linux6733ae71268a27d598cfb3f3339a3c950b9b656dVendor (CNA)
Linux Linux7bad4bda74dc4713f398d3b7624ff05478e3a568Vendor (CNA)
Linux Linuxf00df8500e5a36ba70d336fd34bd2152ea074e5fVendor (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)
almalinux:bpftool4.18.0-553.167.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.167.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt4.18.0-553.167.1.rt7.508.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-core4.18.0-553.167.1.rt7.508.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug4.18.0-553.167.1.rt7.508.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-core4.18.0-553.167.1.rt7.508.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-devel4.18.0-553.167.1.rt7.508.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-modules4.18.0-553.167.1.rt7.508.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-debug-modules-extra4.18.0-553.167.1.rt7.508.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-devel4.18.0-553.167.1.rt7.508.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-modules4.18.0-553.167.1.rt7.508.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-rt-modules-extra4.18.0-553.167.1.rt7.508.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.187-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)
red hat:kernel-rt0:4.18.0-553.167.1.rt7.508.el8_10 · Red Hat:enterprise_linux:8::nfvPackage registry (OSV)
red hat:kernel-rt-core0:4.18.0-553.167.1.rt7.508.el8_10 · Red Hat:enterprise_linux:8::nfvPackage registry (OSV)
red hat:kernel-rt-debug0:4.18.0-553.167.1.rt7.508.el8_10 · Red Hat:enterprise_linux:8::nfvPackage registry (OSV)
red hat:kernel-rt-debug-core0:4.18.0-553.167.1.rt7.508.el8_10 · Red Hat:enterprise_linux:8::nfvPackage registry (OSV)
red hat:kernel-rt-debug-debuginfo0:4.18.0-553.167.1.rt7.508.el8_10 · Red Hat:enterprise_linux:8::nfvPackage registry (OSV)

+8

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×3

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.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02026-09-18
Proof-of-concept repository on GitHubstars:02026-09-19
Proof-of-concept repository on GitHubstars:02026-09-21

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.

  1. Published
  2. First PoC+13 d
  3. TodayNov 4, 2026+61 d
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✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (8 more)

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

All records