NVD / CVE Program· CNA Linux

CVE-2024-49936: net/xen-netback: prevent UAF in xenvif_flush_hash()

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: 0.27% (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 0fa5e94a1811d68fbffa0725efe6d4ca62c03d12, 143edf098b80669d05245b2f2367dd156a83a2c5, 3c4423b0c4b98213b3438e15061e1d08220e6982; azl3 kernel 6.6.51.1-5 on Azure Linux 3.0 6.6.57.1-2; azl3 kernel 6.6.57.1-2 on Azure Linux 3.0 6.6.57.1-2.

Low priority for now. Upgrade to Linux Linux 0fa5e94a1811d68fbffa0725efe6d4ca62c03d12, 143edf098b80669d05245b2f2367dd156a83a2c5, 3c4423b0c4b98213b3438e15061e1d08220e6982; azl3 kernel 6.6.51.1-5 on Azure Linux 3.0 6.6.57.1-2; azl3 kernel 6.6.57.1-2 on Azure Linux 3.0 6.6.57.1-2 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/xen-netback: prevent UAF in xenvif_flush_hash() During the list_for_each_entry_rcu iteration call of xenvif_flush_hash, kfree_rcu does not exist inside the rcu read critical section, so if kfree_rcu is called when the rcu grace period ends during the iteration, UAF occurs when accessing head->next after the entry becomes free. Therefore, to solve this, you need to change it to list_for_each_entry_safe.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

BDU:2024-09004

Published: Oct 21, 2024
Updated: Aug 5, 2026
EPSS: 0.2% · 19th 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 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 7.8
CNA · Linux: 8.8; 1.0 point gap

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

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.

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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.

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 kernelbefore 5.10.227
linux linux kernel5.11 and later · before 5.15.168
linux linux kernel5.16 and later · before 6.1.113
linux linux kernel6.2 and later · before 6.6.55
linux linux kernel6.7 and later · before 6.10.14
linux linux kernel6.11 and later · before 6.11.3

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
- 4.7affected
- 40d8abdee806d496a60ee607a6d01b1cd7fabaf0 and later · before 3c4423b0c4b98213b3438e15061e1d08220e6982affected · git
- 40d8abdee806d496a60ee607a6d01b1cd7fabaf0 and later · before a7f0073fcd12ed7de185ef2c0af9d0fa1ddef22caffected · git
- 40d8abdee806d496a60ee607a6d01b1cd7fabaf0 and later · before a0465723b8581cad27164c9073fd780904cd22d4affected · git
- 40d8abdee806d496a60ee607a6d01b1cd7fabaf0 and later · before efcff6ce7467f01f0753609f420333f3f2cecedaaffected · git
- 40d8abdee806d496a60ee607a6d01b1cd7fabaf0 and later · before 143edf098b80669d05245b2f2367dd156a83a2c5affected · git
- 40d8abdee806d496a60ee607a6d01b1cd7fabaf0 and later · before d408889d4b54f5501e4becc4dbbb9065143fbf4eaffected · git
- 40d8abdee806d496a60ee607a6d01b1cd7fabaf0 and later · before 54d8639af5568fc41c0e274fc3ec9cf86c59fcbbaffected · git
- 40d8abdee806d496a60ee607a6d01b1cd7fabaf0 and later · before 0fa5e94a1811d68fbffa0725efe6d4ca62c03d12affected · git
- before 4.7not 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 6.1.115-1	6.1.115-1
Debian:13	linux	before 6.11.4-1	6.11.4-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
90Now
CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
89Now
CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
85Now

Published before and after this one in the same product

← EarlierCVE-2024-49934Oct 21, 2024 · fs/inode: Prevent dump_mapping() accessing invalid dentry.d_name.name
18Monitor
← EarlierCVE-2024-49935Oct 21, 2024 · ACPI: PAD: fix crash in exit_round_robin()
22Monitor
Later →CVE-2024-49937Oct 21, 2024 · wifi: cfg80211: Set correct chandef when starting CAC
22Monitor

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	0fa5e94a1811d68fbffa0725efe6d4ca62c03d12	Vendor (CNA)
Linux Linux	143edf098b80669d05245b2f2367dd156a83a2c5	Vendor (CNA)
Linux Linux	3c4423b0c4b98213b3438e15061e1d08220e6982	Vendor (CNA)
Linux Linux	54d8639af5568fc41c0e274fc3ec9cf86c59fcbb	Vendor (CNA)
Linux Linux	a0465723b8581cad27164c9073fd780904cd22d4	Vendor (CNA)
Linux Linux	a7f0073fcd12ed7de185ef2c0af9d0fa1ddef22c	Vendor (CNA)
Linux Linux	d408889d4b54f5501e4becc4dbbb9065143fbf4e	Vendor (CNA)
Linux Linux	efcff6ce7467f01f0753609f420333f3f2ceceda	Vendor (CNA)
azl3 kernel 6.6.51.1-5 on Azure Linux 3.0	6.6.57.1-2 · CBL-Mariner Releases	Microsoft (MSRC)
azl3 kernel 6.6.57.1-2 on Azure Linux 3.0	6.6.57.1-2 · CBL-Mariner Releases	Microsoft (MSRC)
cbl2 kernel 5.15.167.1-2 on CBL Mariner 2.0	5.15.173.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
cbl2 kernel 5.15.167.1-2 on CBL-Mariner 2.0	5.15.173.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
cbl2 kernel 5.15.173.1-1 on CBL Mariner 2.0	5.15.173.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.115-1 · 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.

No history yet (it accumulates with the daily EPSS job).

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

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-primary

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

Fix✗ → ✓Sep 28, 2026, 10:09 PM UTC

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

References

git.kernel.org/stable/c/0fa5e94a1811d68fbffa0725efe6d4ca62c03d12

Show all references (9 more)

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

All records