NVD / CVE Program· CNA Linux

CVE-2026-68284: bpf, sockmap: Fix cork use-after-free in tcp_bpf_sendmsg()

Noroxi assessment

Priority: Monitor (action score 31/100)

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 0688e6fe599d2d39147ae9ece97944c6e1815ebf, 2d66a033864e27ab8d5e44cb36f31d9d2413bee4, 54be47e7cbb936429c3bbdfc526ea943954aaf80; azl3 kernel 6.6.143.1-1 on Azure Linux 3.0 6.6.150.1-1.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0688e6fe599d2d39147ae9ece97944c6e1815ebf, 2d66a033864e27ab8d5e44cb36f31d9d2413bee4, 54be47e7cbb936429c3bbdfc526ea943954aaf80; azl3 kernel 6.6.143.1-1 on Azure Linux 3.0 6.6.150.1-1 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: bpf, sockmap: Fix cork use-after-free in tcp_bpf_sendmsg() tcp_bpf_sendmsg() keeps msg_tx across sk_stream_wait_memory(), which drops and reacquires the socket lock. Its error path tries to decide whether msg_tx names the local temporary message by comparing it with the current value of psock->cork. This comparison is unsafe when two threads send on the same socket: Thread A Thread B msg_tx = psock->cork sk_msg_alloc() fails sk_stream_wait_memory() releases the socket lock acquires the socket lock completes the cork psock->cork = NULL frees the cork reacquires the socket lock msg_tx != psock->cork sk_msg_free(msg_tx) The stale cork is therefore mistaken for the local temporary message and freed again. KASAN reported: BUG: KASAN: slab-use-after-free in sk_msg_free+0x49/0x50 Read of size 4 at addr ffff88810c908800 by task poc/90 Call Trace: sk_msg_free+0x49/0x50 tcp_bpf_sendmsg+0x14f5/0x1cc0 __sys_sendto+0x32c/0x3a0 __x64_sys_sendto+0xdb/0x1b0 Allocated by task 89: __kasan_kmalloc+0x8f/0xa0 tcp_bpf_sendmsg+0x16b3/0x1cc0 Freed by task 91: __kasan_slab_free+0x43/0x70 kfree+0x131/0x3c0 tcp_bpf_sendmsg+0xec3/0x1cc0 msg_tx can only name the stack-local tmp or the shared cork. Check for tmp directly so a changed psock->cork cannot turn a shared message into an apparent local one.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

Published: Aug 10, 2026
Updated: Oct 19, 2026
EPSS: 0.1% · 3th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 7.8; 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.

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
- 4.20affected
- 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before 0688e6fe599d2d39147ae9ece97944c6e1815ebfaffected · git
- 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before b2bcbeabfd843d47468fa095b1bd08ddb90cf616affected · git
- 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before 54be47e7cbb936429c3bbdfc526ea943954aaf80affected · git
- 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before ee762f684eefa59de34d9ed93cab08336e834f47affected · git
- 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before cde4d6bcd9b73073c66498f6723c7b364c4dbc18affected · git
- 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before 786d690257ec7a0c839f8710456e444ce3f1348baffected · git
- 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before 752b1159ed5d0c48fe169a3721b96660a9822aa1affected · git
- 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before 2d66a033864e27ab8d5e44cb36f31d9d2413bee4affected · git
- before 4.20not 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 6.1.187-1	6.1.187-1
Debian:12	linux-6.12	before 6.12.101-1~deb12u1	6.12.101-1~deb12u1
Debian:13	linux	before 6.12.101-1	6.12.101-1
Debian:14	linux	before 7.1.6-1	7.1.6-1

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-2026-68278Aug 10, 2026 · drm/dp/mst: fix buffer overflows in sideband chunk accumulation
0Monitor
← EarlierCVE-2026-68279Aug 10, 2026 · drm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers
0Monitor
Later →CVE-2026-68286Aug 10, 2026 · drop_monitor: perform u64_stats updates under IRQ-disabled section
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 / package	Fixed version	Source
Linux Linux	0688e6fe599d2d39147ae9ece97944c6e1815ebf	Vendor (CNA)
Linux Linux	2d66a033864e27ab8d5e44cb36f31d9d2413bee4	Vendor (CNA)
Linux Linux	54be47e7cbb936429c3bbdfc526ea943954aaf80	Vendor (CNA)
Linux Linux	752b1159ed5d0c48fe169a3721b96660a9822aa1	Vendor (CNA)
Linux Linux	786d690257ec7a0c839f8710456e444ce3f1348b	Vendor (CNA)
Linux Linux	b2bcbeabfd843d47468fa095b1bd08ddb90cf616	Vendor (CNA)
Linux Linux	cde4d6bcd9b73073c66498f6723c7b364c4dbc18	Vendor (CNA)
Linux Linux	ee762f684eefa59de34d9ed93cab08336e834f47	Vendor (CNA)
azl3 kernel 6.6.143.1-1 on Azure Linux 3.0	6.6.150.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.187-1 · Debian:12	Package registry (OSV)
debian:linux-6.12	6.12.101-1~deb12u1 · Debian:12	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.

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.

CVE-2026-681170 days aparttipc: clear sock->sk on the failed-insert path in tipc_sk_create()
39Monitor
CVE-2026-681270 days apartila: reload IPv6 header after pskb_may_pull in checksum adjust
39Monitor
CVE-2026-681440 days apartphonet: pep: fix use-after-free in pep_get_sb()
39Monitor
CVE-2026-681560 days apartlibceph: refresh auth->authorizer_buf{,_len} after authorizer update
39Monitor
CVE-2026-683810 days apartksmbd: pin conn during async oplock break notification
39Monitor
CVE-2026-684260 days apartxfrm: fix stale skb->prev after async crypto steals a GSO segment
39Monitor

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-26-0800 · Aug 11, 2026(Linux Kernel Güvenlik Bildirimi)

All national notices →

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: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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— → noneOct 16, 2026, 5:07 PM UTC
Fix✗ → ✓Sep 28, 2026, 10:07 PM UTC

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

References

git.kernel.org/stable/c/0688e6fe599d2d39147ae9ece97944c6e1815ebf

Show all references (7 more)

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

All records