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NVD / CVE Program· CNA Linux

CVE-2026-45991: udf: fix partition descriptor append bookkeeping

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: 0.17% (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 058b451b1039f056d1362c4fec2229e522366ab0, 08841b06fa64d8edbd1a21ca6e613420c90cc4b8, 08fa5d818e5bf53c7ca234d88ba334f32004e9b6; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.141.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 058b451b1039f056d1362c4fec2229e522366ab0, 08841b06fa64d8edbd1a21ca6e613420c90cc4b8, 08fa5d818e5bf53c7ca234d88ba334f32004e9b6; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.141.1-1 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: udf: fix partition descriptor append bookkeeping Mounting a crafted UDF image with repeated partition descriptors can trigger a heap out-of-bounds write in part_descs_loc[]. handle_partition_descriptor() deduplicates entries by partition number, but appended slots never record partnum. As a result duplicate Partition Descriptors are appended repeatedly and num_part_descs keeps growing. Once the table is full, the growth path still sizes the allocation from partnum even though inserts are indexed by num_part_descs. If partnum is already aligned to PART_DESC_ALLOC_STEP, ALIGN(partnum, step) can keep the old capacity and the next append writes past the end of the table. Store partnum in the appended slot and size growth from the next append count so deduplication and capacity tracking follow the same model.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
May 27, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 7th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.8
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.

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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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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 kernel4.18.7 and later · before 4.19
  • linux linux kernel4.19.1 and later · before 6.6.140
  • linux linux kernel6.7 and later · before 6.12.88
  • linux linux kernel6.13 and later · before 7.0.4
  • linux linux kernel4.19

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

    • 7f401f160a9c7a1ff84ba3cb9b2f636d1f5cfb6b, 4.19affected
    • ee4af50ca94f58afc3532662779b9cf80bbe27c8 and later · before ad3c0c4400686f6f37b382aaa48fac2b9aefccbeaffected · git
    • ee4af50ca94f58afc3532662779b9cf80bbe27c8 and later · before 68013a9bd4c01acd42073715f00e1a1992f089eeaffected · git
    • ee4af50ca94f58afc3532662779b9cf80bbe27c8 and later · before e8474cfbac9ada2cdaa4eaedec22aadfa0f58559affected · git
    • ee4af50ca94f58afc3532662779b9cf80bbe27c8 and later · before 058b451b1039f056d1362c4fec2229e522366ab0affected · git
    • ee4af50ca94f58afc3532662779b9cf80bbe27c8 and later · before b5597bb83fc37b5b5da74a4453fa920b932cf39aaffected · git
    • ee4af50ca94f58afc3532662779b9cf80bbe27c8 and later · before 73df74544b55241dca5dd788523e6f5f10bd2b9baffected · git
    • ee4af50ca94f58afc3532662779b9cf80bbe27c8 and later · before 08fa5d818e5bf53c7ca234d88ba334f32004e9b6affected · git
    • ee4af50ca94f58afc3532662779b9cf80bbe27c8 and later · before 08841b06fa64d8edbd1a21ca6e613420c90cc4b8affected · git
    • 4.18.7 and later · before 4.19affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.49.1.el10_26.12.0-211.49.1.el10_2

+96

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-2026-45987May 27, 2026 · KVM: nSVM: Sync interrupt shadow to cached vmcb12 after VMRUN of L2
    22Monitor
  • ← EarlierCVE-2026-45988May 27, 2026 · rxrpc: Fix re-decryption of RESPONSE packets
    39Monitor
  • Later →CVE-2026-45996May 27, 2026 · spi: imx: fix use-after-free on unbind
    31Monitor

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 Linux058b451b1039f056d1362c4fec2229e522366ab0Vendor (CNA)
Linux Linux08841b06fa64d8edbd1a21ca6e613420c90cc4b8Vendor (CNA)
Linux Linux08fa5d818e5bf53c7ca234d88ba334f32004e9b6Vendor (CNA)
Linux Linux4.19Vendor (CNA)
Linux Linux68013a9bd4c01acd42073715f00e1a1992f089eeVendor (CNA)
Linux Linux73df74544b55241dca5dd788523e6f5f10bd2b9bVendor (CNA)
Linux Linuxad3c0c4400686f6f37b382aaa48fac2b9aefccbeVendor (CNA)
Linux Linuxb5597bb83fc37b5b5da74a4453fa920b932cf39aVendor (CNA)
Linux Linuxe8474cfbac9ada2cdaa4eaedec22aadfa0f58559Vendor (CNA)
azl3 kernel 6.6.139.1-1 on Azure Linux 3.06.6.141.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:bpftool4.18.0-553.155.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.155.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.155.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.155.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.155.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.155.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.155.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.155.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.155.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.155.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-553.155.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-553.155.1.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.176-1 · Debian:12Package registry (OSV)
red hat:bpftool0:4.18.0-553.155.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:bpftool-debuginfo0:4.18.0-553.155.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel0:4.18.0-553.155.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-abi-stablelists0:4.18.0-553.155.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-core0:4.18.0-553.155.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug0:4.18.0-553.155.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-core0:4.18.0-553.155.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)

+7

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).

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

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-787 · Out-of-bounds Write

CVSS vector

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

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

References

Show all references (8 more)

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

All records