Skip to content
Noroxi
CVE.org (no NVD analysis yet)· CNA Linux

CVE-2026-99041: ip6_gre: remove obsolete ERSPAN PMTU update

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: 0.17% (FIRST EPSS).
  • Fixed version: Linux Linux 2d06cb25a497d3a7034ef9d172626c2d6620a0f1, 2e151c74bcc53e3ed313bd1c21b0d5bb442edbc0, 8bc60db48e8cba35488bbd6e1f94aa990afa275a; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 6.6.161.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 2d06cb25a497d3a7034ef9d172626c2d6620a0f1, 2e151c74bcc53e3ed313bd1c21b0d5bb442edbc0, 8bc60db48e8cba35488bbd6e1f94aa990afa275a; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 6.6.161.1-1 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: ip6_gre: remove obsolete ERSPAN PMTU update A tc tunnel_key action can attach a METADATA_IP_TUNNEL dst to an skb, and mirred can redirect it to a native ip6erspan device. The legacy PMTU update in ip6erspan_tunnel_xmit() treats that metadata dst as a route. Since it has no output device, dst_dev(dst)->mtu dereferences NULL. On v7.2 with KASAN, an initial UID/GID 65534 process with CapEff 0 used self-created user and network namespaces to trigger: KASAN: null-ptr-deref RIP: ip6erspan_tunnel_xmit+0x10fc/0x2cc0 Kernel panic - not syncing: Fatal exception in interrupt The update is obsolete. Commit fe1a4ca0a2b7 ("ip6_gre: process toobig in a better way") changed IPv6 GRE Too Big handling to update the underlay route and removed the equivalent block from __gre6_xmit(). ip6_tnl_xmit() then propagates the underlay PMTU to the overlay route. Remove the stale ERSPAN copy and its now-unused dst variable. This eliminates the metadata-dst dereference and keeps ERSPAN aligned with IPv6 GRE PMTU handling.

—No exploit Fix available
Published
Oct 23, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 6th 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

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-99041

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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 help

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

    • 4.16affected
    • 5a963eb61b7c39e6c422b6e48619d19d04719358 and later · before 2e151c74bcc53e3ed313bd1c21b0d5bb442edbc0affected · git
    • 5a963eb61b7c39e6c422b6e48619d19d04719358 and later · before ba72ed1c8476ce68eb7152dfcbc5330cefcbaa91affected · git
    • 5a963eb61b7c39e6c422b6e48619d19d04719358 and later · before b14a682ad7d45345701e08f9279d483a1da8b36caffected · git
    • 5a963eb61b7c39e6c422b6e48619d19d04719358 and later · before f5b143f4cd3fb7673df8d727550478a4b762908aaffected · git
    • 5a963eb61b7c39e6c422b6e48619d19d04719358 and later · before 2d06cb25a497d3a7034ef9d172626c2d6620a0f1affected · git
    • 5a963eb61b7c39e6c422b6e48619d19d04719358 and later · before 8f27260b989f488760289276377db24fbfb20bfaaffected · git
    • 5a963eb61b7c39e6c422b6e48619d19d04719358 and later · before 8bc60db48e8cba35488bbd6e1f94aa990afa275aaffected · git
    • before 4.16not affected · semver
    • 5.15.224 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.

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.115-26.12.115-2
Debian:14linuxbefore 7.2.11-17.2.11-1

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-2026-99039Oct 23, 2026 · memstick: core: wait for request completion before freeing card
    0Monitor
  • ← EarlierCVE-2026-99040Oct 23, 2026 · KEYS: Fix add_key() race with keyring restriction
    0Monitor
  • Later →CVE-2026-99042Oct 23, 2026 · io_uring/net: populate CONNECT filter fields for 24-byte sockaddr_in6
    33Monitor

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 Linux2d06cb25a497d3a7034ef9d172626c2d6620a0f1Vendor (CNA)
Linux Linux2e151c74bcc53e3ed313bd1c21b0d5bb442edbc0Vendor (CNA)
Linux Linux8bc60db48e8cba35488bbd6e1f94aa990afa275aVendor (CNA)
Linux Linux8f27260b989f488760289276377db24fbfb20bfaVendor (CNA)
Linux Linuxb14a682ad7d45345701e08f9279d483a1da8b36cVendor (CNA)
Linux Linuxba72ed1c8476ce68eb7152dfcbc5330cefcbaa91Vendor (CNA)
Linux Linuxf5b143f4cd3fb7673df8d727550478a4b762908aVendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.06.6.161.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.12.115-2 · Debian:13Package registry (OSV)
debian:linux7.2.11-1 · Debian:14Package 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.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 9, 2026+17 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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

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. Exploit maturity— → none
  2. Fix✗ → ✓

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

References

Show all references (6 more)

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

All records