Unknown

CVE-2026-89525 — udf: reject VAT indexes equal to the entry count

In the Linux kernel, the following vulnerability has been resolved: udf: reject VAT indexes equal to the entry count UDF 1.50 virtual partition mapping uses the VAT as an array of physical block mappings. s_num_entries stores the number of entries in that array, not the highest valid index. The valid VAT indexes are therefore below s_num_entries. udf_get_pblock_virt15() currently rejects only indexes greater than s_num_entries. A crafted image can request index s_num_entries, pass the bounds check, and make the kernel read one entry past the allocated VAT table. Change the check to reject block >= s_num_entries, so the count is handled as an exclusive upper bound. A crafted UDF image reproduced this on origin/master commit 0e35b9b6ec0ffcc5e23cbdec09f5c622ad532b53 with a KASAN slab-out-of-bounds report in udf_get_pblock_virt15(). Trail of Bits has a reproducer that triggers kernel panic demonstrating the bug, and can share it if needed.

Published Sep 11, 2026 · Updated Oct 19, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.18%

ahead of 8% of scored CVEs · Oct 23, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < f64e01a90326bb85a3cc8aa0199931dc2f15b589≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 8a8c1c42a34349a0626d910abbad5a29136446b7≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 19f36c6453cd88fe6d60ef36ab1f1cad8ddf4ce4≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < b77b83f5529a26d084d64ece98abd6f0cc86e053≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 9193368408d792cec2057628d87862140fb1ce1c≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < b95c33a4e743874f1b0a45bf2aaa4da553552bd1≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 1bd7947f1463c21edafa256d0fbec5b99215e2b6≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < cac0cb07f29ccfb373fd4a36c81e908ef3ce608c and 1 more version 2.6.12	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 23, 2026 · 8 reading(s) · max 0.18%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 15, 2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 11, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× References added · Oct 19, 2026 – Oct 19, 2026
1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

10 on the record

nvd.nist.gov/vuln/detail/CVE-2026-89525
GitHub Security Advisories
git.kernel.org/stable/c/1bd7947f1463c21edafa256d0fbec5b99215e2b6
NIST National Vulnerability Database
git.kernel.org/stable/c/cac0cb07f29ccfb373fd4a36c81e908ef3ce608c
NIST National Vulnerability Database
git.kernel.org/stable/c/19f36c6453cd88fe6d60ef36ab1f1cad8ddf4ce4
NIST National Vulnerability Database
git.kernel.org/stable/c/f64e01a90326bb85a3cc8aa0199931dc2f15b589
NIST National Vulnerability Database
git.kernel.org/stable/c/b77b83f5529a26d084d64ece98abd6f0cc86e053
NIST National Vulnerability Database
git.kernel.org/stable/c/8a8c1c42a34349a0626d910abbad5a29136446b7
NIST National Vulnerability Database
git.kernel.org/stable/c/9193368408d792cec2057628d87862140fb1ce1c
NIST National Vulnerability Database
git.kernel.org/stable/c/b95c33a4e743874f1b0a45bf2aaa4da553552bd1
NIST National Vulnerability Database
github.com/advisories/GHSA-383p-4f3r-q68w
GitHub Security Advisories

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Unknown CVE-2026-99086 dm-integrity: validate the superblock on resume 1d
Unknown CVE-2026-99087 dm-integrity: fix NULL pointer dereference when the 'R' flag is used 1d
Unknown CVE-2026-99080 fs: Free any excess xarray nodes in clear_inode() 1d
Unknown CVE-2026-99084 readdir: take no inode lock on an immutable directory 1d
Unknown CVE-2026-99085 sched_ext: Fix CPU hotplug hang when a dying CPU's tasks sit in the BPF scheduler 1d
Critical CVE-2026-99079 net/mlx5e: Prevent stale XSK buffer release on refill retry 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-89525 is "udf: reject VAT indexes equal to the entry count", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.18% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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