vsock/virtio: fix zerocopy completion for multi-skb sends
In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: fix zerocopy completion for multi-skb sends When a large message is fragmented into multiple skbs, the zerocopy uarg is only allocated and attached to the last skb in the loop. Non-final skbs carry pinned user pages with no completion tracking, so the kernel has no way to notify userspace when those pages are safe to reuse. If the loop breaks early the uarg is never allocated at all, leaking pinned pages with no completion notification. Fix this by following the approach used by TCP: allocate the zerocopy uarg (if not provided by the caller) before the send loop and attach it to every skb via skb_zcopy_set(), which takes a reference per skb. Each skb's completion properly decrements the refcount, and the notification only fires after the last skb is freed. On failure, if no data was sent, the uarg is cleanly aborted via net_zcopy_put_abort(). This issue was initially discovered by sashiko while reviewing commit 1cb36e252211 ("vsock/virtio: fix MSG_ZEROCOPY pinned-pages accounting") but was pre-existing.
- Published
- Jul 13, 2026
- Updated
- Aug 18, 2026
- EPSS
- 0.2% · 8th percentile
- CWE
- CWE-401
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Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel6.7 and later · before 6.18.34
- linux linux kernel6.19 and later · before 7.0.11
- linux linux kernel7.1
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
- 6.7affected
- 581512a6dc939ef122e49336626ae159f3b8a345 and later · before 293fe8f2d1b5ac464ca16a8eba09571bbbb34ba9affected · git
- 581512a6dc939ef122e49336626ae159f3b8a345 and later · before 76b995bc57bd90cb6e954e1966fbd8786da47f0daffected · git
- 581512a6dc939ef122e49336626ae159f3b8a345 and later · before b3155f2b78db21e99256bcf7eb902f24ff6d5338affected · git
- 581512a6dc939ef122e49336626ae159f3b8a345 and later · before ae38d9179190a956e2a87a69ef1dd6f451b51c4daffected · git
- before 6.7not affected · semver
- 6.12.97 and later · up to and including 6.12.*not affected · semver
- 6.18.34 and later · up to and including 6.18.*not affected · semver
- 7.0.11 and later · up to and including 7.0.*not affected · semver
- 7.1 and laternot affected · original_commit_for_fix
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-6.12 | before 6.12.100-1~deb12u1 | 6.12.100-1~deb12u1 |
| Debian:13 | linux | before 6.12.100-1 | 6.12.100-1 |
| Debian:14 | linux | before 7.0.12-1 | 7.0.12-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
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- CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV83Now
- CVE-2019-13272In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to creKEV77This week
- CVE-2013-6282The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the v6k and v7 ARM platforms do not validate certain addKEV77This week
- CVE-2013-2094The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9 uses an incorrect integer data type, which allows loKEV77This week
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 | 293fe8f2d1b5ac464ca16a8eba09571bbbb34ba9 | Vendor (CNA) |
| Linux Linux | 76b995bc57bd90cb6e954e1966fbd8786da47f0d | Vendor (CNA) |
| Linux Linux | ae38d9179190a956e2a87a69ef1dd6f451b51c4d | Vendor (CNA) |
| Linux Linux | b3155f2b78db21e99256bcf7eb902f24ff6d5338 | Vendor (CNA) |
| debian:linux | 6.12.100-1 · Debian:13 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.100-1~deb12u1 · Debian:12 | Package registry (OSV) |
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 ×2
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.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:0 | 2026-08-14 |
| Proof-of-concept repository on GitHub | stars:4 | 2026-08-19 |
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.
- Published
- First PoC+31 d
- TodayOct 1, 2026+80 d
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 researchersFinders, 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.
- TR-26-0550 · Jul 14, 2026(Linux Kernel Güvenlik Bildirimi)
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
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-401 · Missing Release of Memory after Effective LifetimeCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
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
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/293fe8f2d1b5ac464ca16a8eba09571bbbb34ba9
- git.kernel.org/stable/c/76b995bc57bd90cb6e954e1966fbd8786da47f0d
- git.kernel.org/stable/c/ae38d9179190a956e2a87a69ef1dd6f451b51c4d
- git.kernel.org/stable/c/b3155f2b78db21e99256bcf7eb902f24ff6d5338
- github.com/MaherAzzouzi/vsockdrop
Vendor advisories and official records. Exploit/PoC links are deliberately left out.