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CVE-2026-68136· NVD / CVE Program· CNA Linux

net: gro: fix double aggregation of flush-marked skbs

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.53% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Linux Linux 107e1a469f53a2a70874f3f12bf6fcd23925da1d, 7fc7e35212cf58c134310fb47566a844297ceae9, a4dfd46cc8f08a29c6183794790547d0945f3d45; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 107e1a469f53a2a70874f3f12bf6fcd23925da1d, 7fc7e35212cf58c134310fb47566a844297ceae9, a4dfd46cc8f08a29c6183794790547d0945f3d45; 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: net: gro: fix double aggregation of flush-marked skbs Commit 0ab03f353d36 ("net-gro: Fix GRO flush when receiving a GSO packet.") added a flush check to skb_gro_receive(), but skb_gro_receive_list() lacks the same validation. As a result, packets marked with NAPI_GRO_CB(skb)->flush may still be re-aggregated. This allows already-GRO'd packets with existing frag_list to be re-aggregated into a new GRO session, corrupting the frag_list chain structure. When skb_segment() attempts to unpack these malformed packets, it encounters invalid state and triggers a kernel panic. Scenario (Tethering/Device forwarding): 1. Driver: Generated aggregated packet P1 via LRO with frag_list 2. Dev A: Receives aggregated fraglist packet and flush flag set 3. Dev A: Re-enters GRO, skb_gro_receive_list() is called 4. Missing flush check allows re-aggregation despite flush flag 5. Frag_list chain becomes corrupted (loops or dangling refs) 6. Dev B: TX path calls skb_segment(), crashes on corrupted frag_list Root cause in skb_segment(): The check at line ~4891: if (hsize <= 0 && i >= nfrags && skb_headlen(list_skb) && (skb_headlen(list_skb) == len || sg)) { When frag_list is corrupted by double aggregation, when list_skb is a NULL pointer from skb->next, skb_headlen(list_skb) dereference NULL/corrupted pointers occurs. Call Trace: skb_headlen(NULL skb) skb_segment tcp_gso_segment tcp4_gso_segment inet_gso_segment skb_mac_gso_segment __skb_gso_segment skb_gso_segment validate_xmit_skb validate_xmit_skb_list sch_direct_xmit qdisc_restart __qdisc_run qdisc_run net_tx_action Fix: Add NAPI_GRO_CB(skb)->flush validation to the early-return check in skb_gro_receive_list(), matching the defensive programming pattern of skb_gro_receive().

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Aug 10, 2026
Updated
Oct 16, 2026
EPSS
0.5% · 44th percentile
CWE
—

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
9.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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-2026-68136

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

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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

    • 5.6affected
    • 3a1296a38d0cf62bffb9a03c585cbd5dbf15d596 and later · before 7fc7e35212cf58c134310fb47566a844297ceae9affected · git
    • 3a1296a38d0cf62bffb9a03c585cbd5dbf15d596 and later · before d1fb23f8f794ac4683127bd49a6422bd87e0ac02affected · git
    • 3a1296a38d0cf62bffb9a03c585cbd5dbf15d596 and later · before db3e82da616f52e2b27e25e7be3fde2f2a5e54d6affected · git
    • 3a1296a38d0cf62bffb9a03c585cbd5dbf15d596 and later · before 107e1a469f53a2a70874f3f12bf6fcd23925da1daffected · git
    • 3a1296a38d0cf62bffb9a03c585cbd5dbf15d596 and later · before a4dfd46cc8f08a29c6183794790547d0945f3d45affected · git
    • 3a1296a38d0cf62bffb9a03c585cbd5dbf15d596 and later · before fc0c0f7a207f0cd2d2aa725696c907f7d03af9e0affected · git
    • 3a1296a38d0cf62bffb9a03c585cbd5dbf15d596 and later · before e751256486d0ded20f5a9f9863467f1dce65142faffected · git
    • before 5.6not affected · semver
    • 5.10.266 and later · up to and including 5.10.*not affected · semver

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 6.12.101-1~deb12u16.12.101-1~deb12u1
Debian:13linuxbefore 6.12.101-16.12.101-1
Debian:14linuxbefore 7.1.6-17.1.6-1

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-2026-68129Aug 10, 2026 · gve: fix Rx queue stall on alloc failure
    30Monitor
  • ← EarlierCVE-2026-68131Aug 10, 2026 · rbd: Reset positive result codes to zero in object map update path
    30Monitor
  • Later →CVE-2026-68138Aug 10, 2026 · net/sched: serialize qdisc_rtab_list against concurrent get/put
    31Monitor

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 Linux107e1a469f53a2a70874f3f12bf6fcd23925da1dVendor (CNA)
Linux Linux7fc7e35212cf58c134310fb47566a844297ceae9Vendor (CNA)
Linux Linuxa4dfd46cc8f08a29c6183794790547d0945f3d45Vendor (CNA)
Linux Linuxd1fb23f8f794ac4683127bd49a6422bd87e0ac02Vendor (CNA)
Linux Linuxdb3e82da616f52e2b27e25e7be3fde2f2a5e54d6Vendor (CNA)
Linux Linuxe751256486d0ded20f5a9f9863467f1dce65142fVendor (CNA)
Linux Linuxfc0c0f7a207f0cd2d2aa725696c907f7d03af9e0Vendor (CNA)
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-6.126.12.101-1~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).

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

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

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. SSVC exploitation— → 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