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NVD / CVE Program· CNA Linux

CVE-2022-49649: xen/netback: avoid entering xenvif_rx_next_skb() with an empty rx queue

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.26% (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 5a071aefd6414af5a20321ab58a0557b81993687, 7425479d20f9e96f7c3ec8e8a93fe0d7478724cb, 94e8100678889ab428e68acadf042de723f094b9.

Low priority for now. Upgrade to Linux Linux 5a071aefd6414af5a20321ab58a0557b81993687, 7425479d20f9e96f7c3ec8e8a93fe0d7478724cb, 94e8100678889ab428e68acadf042de723f094b9 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: xen/netback: avoid entering xenvif_rx_next_skb() with an empty rx queue xenvif_rx_next_skb() is expecting the rx queue not being empty, but in case the loop in xenvif_rx_action() is doing multiple iterations, the availability of another skb in the rx queue is not being checked. This can lead to crashes: [40072.537261] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [40072.537407] IP: xenvif_rx_skb+0x23/0x590 [xen_netback] [40072.537534] PGD 0 P4D 0 [40072.537644] Oops: 0000 [#1] SMP NOPTI [40072.537749] CPU: 0 PID: 12505 Comm: v1-c40247-q2-gu Not tainted 4.12.14-122.121-default #1 SLE12-SP5 [40072.537867] Hardware name: HP ProLiant DL580 Gen9/ProLiant DL580 Gen9, BIOS U17 11/23/2021 [40072.537999] task: ffff880433b38100 task.stack: ffffc90043d40000 [40072.538112] RIP: e030:xenvif_rx_skb+0x23/0x590 [xen_netback] [40072.538217] RSP: e02b:ffffc90043d43de0 EFLAGS: 00010246 [40072.538319] RAX: 0000000000000000 RBX: ffffc90043cd7cd0 RCX: 00000000000000f7 [40072.538430] RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffffc90043d43df8 [40072.538531] RBP: 000000000000003f R08: 000077ff80000000 R09: 0000000000000008 [40072.538644] R10: 0000000000007ff0 R11: 00000000000008f6 R12: ffffc90043ce2708 [40072.538745] R13: 0000000000000000 R14: ffffc90043d43ed0 R15: ffff88043ea748c0 [40072.538861] FS: 0000000000000000(0000) GS:ffff880484600000(0000) knlGS:0000000000000000 [40072.538988] CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033 [40072.539088] CR2: 0000000000000080 CR3: 0000000407ac8000 CR4: 0000000000040660 [40072.539211] Call Trace: [40072.539319] xenvif_rx_action+0x71/0x90 [xen_netback] [40072.539429] xenvif_kthread_guest_rx+0x14a/0x29c [xen_netback] Fix that by stopping the loop in case the rx queue becomes empty.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Feb 26, 2025
Updated
Jun 17, 2026
EPSS
0.2% · 18th percentile

Report tools

JSON

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
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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-2022-49649

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.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.9 and later · before 4.9.324
  • linux linux kernel4.10 and later · before 4.14.289
  • linux linux kernel4.15 and later · before 4.19.253
  • linux linux kernel4.20 and later · before 5.4.207
  • linux linux kernel5.5 and later · before 5.10.132
  • linux linux kernel5.11 and later · before 5.15.56
  • linux linux kernel5.16 and later · before 5.18.13
  • linux linux kernel5.19

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

    • 4.9affected
    • 98f6d57ced73b723551568262019f1d6c8771f20 and later · before c0fcceb5f3f1ec197c014fe218c2f28108cacd27affected · git
    • 98f6d57ced73b723551568262019f1d6c8771f20 and later · before d5320c6a27aa975aff740f9cb481dcbde48f4348affected · git
    • 98f6d57ced73b723551568262019f1d6c8771f20 and later · before 5a071aefd6414af5a20321ab58a0557b81993687affected · git
    • 98f6d57ced73b723551568262019f1d6c8771f20 and later · before 7425479d20f9e96f7c3ec8e8a93fe0d7478724cbaffected · git
    • 98f6d57ced73b723551568262019f1d6c8771f20 and later · before b9c32a6886af79d6e0ad87a7b01800ed079cdd02affected · git
    • 98f6d57ced73b723551568262019f1d6c8771f20 and later · before b99174ac57fe5d8867448c03b23828e63f24cb1caffected · git
    • 98f6d57ced73b723551568262019f1d6c8771f20 and later · before f0b5c819b062df8bf5f2acf4697e3871cb3722daaffected · git
    • 98f6d57ced73b723551568262019f1d6c8771f20 and later · before 94e8100678889ab428e68acadf042de723f094b9affected · git
    • before 4.9not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.18.14-15.18.14-1

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-2022-49647Feb 26, 2025 · cgroup: Use separate src/dst nodes when preloading css_sets for migration
    31Monitor
  • ← EarlierCVE-2022-49648Feb 26, 2025 · tracing/histograms: Fix memory leak problem
    22Monitor
  • Later →CVE-2022-49650Feb 26, 2025 · dmaengine: qcom: bam_dma: fix runtime PM underflow
    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 / packageFixed versionSource
Linux Linux5a071aefd6414af5a20321ab58a0557b81993687Vendor (CNA)
Linux Linux7425479d20f9e96f7c3ec8e8a93fe0d7478724cbVendor (CNA)
Linux Linux94e8100678889ab428e68acadf042de723f094b9Vendor (CNA)
Linux Linuxb99174ac57fe5d8867448c03b23828e63f24cb1cVendor (CNA)
Linux Linuxb9c32a6886af79d6e0ad87a7b01800ed079cdd02Vendor (CNA)
Linux Linuxc0fcceb5f3f1ec197c014fe218c2f28108cacd27Vendor (CNA)
Linux Linuxd5320c6a27aa975aff740f9cb481dcbde48f4348Vendor (CNA)
Linux Linuxf0b5c819b062df8bf5f2acf4697e3871cb3722daVendor (CNA)
debian:linux5.18.14-1 · 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).

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-476 · NULL Pointer Dereference

CVSS 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

  1. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records