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

CVE-2026-98900: xen/gntalloc: validate grant count before allocation

Noroxi assessment

Priority: Monitor (action score 0/100)

  • 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: 0.17% (FIRST EPSS).
  • Fixed version: Linux Linux 2299822f3f466b5dcad2377bf63986199f881a6b, 231542f4e43cf9837cb520664545e85fbe666b7b, 641de086a05f349de7fc548612432bc2fed721ca; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.159.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 2299822f3f466b5dcad2377bf63986199f881a6b, 231542f4e43cf9837cb520664545e85fbe666b7b, 641de086a05f349de7fc548612432bc2fed721ca; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.159.1-1 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: xen/gntalloc: validate grant count before allocation gntalloc_ioctl_alloc() allocates the grant-id array before checking whether the requested count fits within the global grant limit. Counts above that limit cannot succeed, so reject them before the user-controlled allocation reaches kcalloc(). Use a subtraction-based check while holding gref_mutex so adding the requested count cannot wrap. Also cast the count before advancing the per-file index so the page-size multiplication is performed in 64-bit arithmetic.

—No exploit Fix available
Published
Oct 23, 2026
Updated
Oct 26, 2026
EPSS
0.1% · 7th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

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

  • Linux Linux

    • 2.6.39affected
    • dd3140588d9551235ebc2a0dacdca098e7677573 and later · before e2806390aa1c4d5b3f7a68f10a56ae12c71c00d8affected · git
    • dd3140588d9551235ebc2a0dacdca098e7677573 and later · before 71a0cf87e19fb35c4292ca88985e376e613c900aaffected · git
    • dd3140588d9551235ebc2a0dacdca098e7677573 and later · before 641de086a05f349de7fc548612432bc2fed721caaffected · git
    • dd3140588d9551235ebc2a0dacdca098e7677573 and later · before 720554c04acba80018ded069d3e0984bebaee891affected · git
    • dd3140588d9551235ebc2a0dacdca098e7677573 and later · before 84d5727cef8eb9c8a28210ad248f1c70b223b065affected · git
    • dd3140588d9551235ebc2a0dacdca098e7677573 and later · before 231542f4e43cf9837cb520664545e85fbe666b7baffected · git
    • dd3140588d9551235ebc2a0dacdca098e7677573 and later · before 2299822f3f466b5dcad2377bf63986199f881a6baffected · git
    • before 2.6.39not affected · semver
    • 5.10.271 and later · up to and including 5.10.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

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-2026-98898Oct 23, 2026 · drm/amd/pm/si: Don't schedule thermal work when queue isn't initialized
    0Monitor
  • ← EarlierCVE-2026-98899Oct 23, 2026 · netfilter: ipset: mark the rcu locked areas properly
    31Monitor
  • Later →CVE-2026-98901Oct 23, 2026 · ksmbd: fix lease break and ack state handling
    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 / packageFixed versionSource
Linux Linux2299822f3f466b5dcad2377bf63986199f881a6bVendor (CNA)
Linux Linux231542f4e43cf9837cb520664545e85fbe666b7bVendor (CNA)
Linux Linux641de086a05f349de7fc548612432bc2fed721caVendor (CNA)
Linux Linux71a0cf87e19fb35c4292ca88985e376e613c900aVendor (CNA)
Linux Linux720554c04acba80018ded069d3e0984bebaee891Vendor (CNA)
Linux Linux84d5727cef8eb9c8a28210ad248f1c70b223b065Vendor (CNA)
Linux Linuxe2806390aa1c4d5b3f7a68f10a56ae12c71c00d8Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.06.6.159.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.1.190-1 · 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.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 8, 2026+16 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.

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

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. Exploit maturity— → none
  2. Fix✗ → ✓

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

References

Show all references (6 more)

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

All records