High Memory corruption

CVE-2026-64322 — udf: validate sparing table length as an entry count, not a byte count

In the Linux kernel, the following vulnerability has been resolved: udf: validate sparing table length as an entry count, not a byte count udf_load_sparable_map() accepts a sparing table when sizeof(*st) + le16_to_cpu(st->reallocationTableLen) > sb->s_blocksize is false, i.e. it treats reallocationTableLen as a number of BYTES that must fit in the block. But the table is walked as an array of 8-byte sparingEntry elements: for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) { struct sparingEntry *entry = &st->mapEntry[i]; ... entry->origLocation ... } in udf_get_pblock_spar15() and udf_relocate_blocks(). A reallocationTableLen of N therefore passes the check whenever sizeof(*st) + N <= blocksize, yet the consumers index sizeof(*st) + N * sizeof(struct sparingEntry) bytes -- up to ~8x the block. On a crafted UDF image this is an out-of-bounds read in udf_get_pblock_spar15(); udf_relocate_blocks() additionally feeds the same length to udf_update_tag(), whose crc_itu_t() reads far past the block, and its memmove() through st->mapEntry[] is an out-of-bounds write. Validate reallocationTableLen as the entry count it is, with struct_size().

Published Jul 25, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · 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

Technical severity (high)+6

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

—

No EPSS score.

Affects

Linux

Linux and 1 more

CVSS base

7.8

High · 2 source(s)

Remediation

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

Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)

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, Linux Linux Kernel).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	version b1c5701ad6b3e5d21d16f65475651cfaaa41e7aa≥ 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 and < 2d726135099313958f8975532a2e15322ff150ce≥ 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 and < 7285276aa50d2839afb5957ffd491ad282dc8f72≥ 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 and < 2a219acb2ce674d99bbd1b7b35ed8c384dac7200≥ 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 and < 04f4599a9efb90992d072a814960edf0cd62805d≥ 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 and < 7f7774b9da0ef17b87bfa238cf966ad0b3376150≥ 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 and < 3ec997bd5508e9b25210b5bbec89031629cdb093version e240873cb4a9fd18de60a817100a96fe670d4359 and 11 more version 9ae30e324a96d0328a575329d7a95a09b3318601≥ 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 and < 0a9b79a951cfd70a9d31ca01ae2d08a20bb730e9version a9f1af04f086656246f30354fb4564ce3b08c4a0version 4836ee563d65bb492f907cbe267a5761b9693e4d≥ 2.6.32.60 and < 2.6.33≥ 2.6.34.14 and < 2.6.35≥ 3.0.37 and < 3.1≥ 3.2.23 and < 3.3≥ 3.4.5 and < 3.5version 3.5≥ 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 and < eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e	Vulnerable	CVE Program (cve.org) e CISA ADP
Linux	Linux Kernel	≥ 2.6.34.14 and < 2.6.35≥ 2.6.32.60 and < 2.6.33≥ 3.0.37 and < 3.1≥ 3.2.23 and < 3.3≥ 3.4.5 and < 3.5≥ 3.5.1 and < 5.10.261≥ 5.11 and < 5.15.212≥ 5.16 and < 6.1.178 and 8 more ≥ 6.2 and < 6.6.145≥ 6.7 and < 6.12.96≥ 6.13 and < 6.18.39≥ 6.19 and < 7.1.4version 3.5version 3.5-rc5version 3.5-rc6version 3.5-rc7	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
7.8	CVSS 3.1	High	1.8	5.9	416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
7.8	CVSS 3.1	High	—	—	Linux via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-787 · Out-of-bounds Write

Other CVEs with this weakness →

Detection

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

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.

endpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
Fix documented
Oct 15, 2026 · NIST National Vulnerability Database
CVSS changed · 7.8
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Jul 25, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

8 on the record

git.kernel.org/stable/c/04f4599a9efb90992d072a814960edf0cd62805d
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/2d726135099313958f8975532a2e15322ff150ce
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/0a9b79a951cfd70a9d31ca01ae2d08a20bb730e9
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/7285276aa50d2839afb5957ffd491ad282dc8f72
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/2a219acb2ce674d99bbd1b7b35ed8c384dac7200
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/3ec997bd5508e9b25210b5bbec89031629cdb093
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/7f7774b9da0ef17b87bfa238cf966ad0b3376150
Patch, NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Memory corruption
same class

CWE-787
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 11h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 11h
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 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 FIRST EPSS score.
No CISA SSVC assessment.
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-2026-64322 is "udf: validate sparing table length as an entry count, not a byte count", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. 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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