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CVE.org (no NVD analysis yet)· CNA redhat

CVE-2026-120831: Libslirp: libslirp: queue pointer corruption in if_output() leading to denial of service

MediumCVSS 6.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 26/100)

  • 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 on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: azl3 libslirp 4.9.6-1 on Azure Linux 3.0 4.9.7-1.

Low priority for now. Upgrade to azl3 libslirp 4.9.6-1 on Azure Linux 3.0 4.9.7-1 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

A flaw was found in libslirp in if_output(). When moving a session from the fast queue to the batch queue, the code unlinked and reinserted an arbitrary packet via ifm->m_nextpkt instead of the session queue head, corrupting queue pointers. A guest generating burst traffic could crash the host networking process, causing a denial of service.

Published
Nov 3, 2026
Updated
Nov 5, 2026
EPSS
0.2% · 18th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 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.

CNA vs NVD score

NVD
—
CNA · redhat
6.5
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.

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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 (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • Red Hat Red Hat Enterprise Linux 10

    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 8

    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 9

    • all versionsaffected

  • Red Hat Red Hat OpenShift Container Platform 4

    • all versionsaffected
    • all versionsaffected
    • all versionsaffected

  • Red Hat Red Hat OpenShift Container Platform 5

    • all versionsaffected

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12libslirpfrom 0—

Same product

red hat: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-10230Samba: command injection in wins server hook script
    52Plan
  • CVE-2026-4631Cockpit: cockpit: unauthenticated remote code execution due to ssh command-line argument injection
    44Plan
  • CVE-2026-76578Ipa: freeipa: freeipa: unauthenticated ldap client can obtain administrator credentials via the self-managed-token aci
    39Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-120740Nov 2, 2026 · Hivex: hivex: denial of service via out-of-bounds read in big-data block processing
    8Monitor
  • ← EarlierCVE-2026-120830Nov 3, 2026 · Libslirp: libslirp: out-of-bounds heap read in icmp_forward_error() leading to information disclosure
    29Monitor
  • Later →CVE-2026-119843Nov 3, 2026 · Gst-plugins-good: assertion failures in FLV demuxer when parsing malformed enhanced audio/video tags
    26Monitor

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
azl3 libslirp 4.9.6-1 on Azure Linux 3.04.9.7-1 · Release NotesMicrosoft (MSRC)

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.

  1. Published
  2. Fix recorded+9 d
  3. TodayNov 13, 2026+11 d
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.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-1197774 days apartGstreamer1-plugins-bad-free: gstreamer1-plugins-bad-free: stack buffer overflow in h.266/vvc parser
    35Monitor
  • CVE-2026-8647620 days apartGstreamer1-plugins-base: gst-plugins-base: heap buffer overflow via unvalidated gstvideometa plane extents in gst_video_frame_map_id and video_meta_deserialize
    33Monitor
  • CVE-2026-8162746 days apartQemu-kvm: vapic writable rom alias can escape the option-rom window and expose locked smram
    32Monitor
  • CVE-2026-10125828 days apartGhostscript: ghostscript: -dsafer sandbox bypass via type 5 shading oob write and procedure-stream use-after-free
    31Monitor
  • CVE-2026-9718540 days apartGimp: gimp: out-of-bounds write in gimpressionist plugin via crafted preset file
    31Monitor
  • CVE-2026-1822097 days apartBinutils: binutils: out-of-bounds write in bfd dlx elf backend relocation processing
    31Monitor

Not on record for this CVE: public bounty program.

Technical details

Attack conditions

  • Someone on the same network segment 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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/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. Fix✗ → ✓
  2. SSVC exploitation— → none
  3. Exploit maturity— → none

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

References

Show all references (2 more)

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

All records