CVE Intelligence
High Memory corruption

CVE-2026-46303 — isofs: validate Rock Ridge CE continuation extent against volume size

In the Linux kernel, the following vulnerability has been resolved: isofs: validate Rock Ridge CE continuation extent against volume size rock_continue() reads rs->cont_extent verbatim from the Rock Ridge CE record and passes it to sb_bread() without checking that the block number is within the mounted ISO 9660 volume. commit e595447e177b ("[PATCH] rock.c: handle corrupted directories") added cont_offset and cont_size rejection for the CE continuation but did not validate the extent block number itself. commit f54e18f1b831 ("isofs: Fix infinite looping over CE entries") later capped the CE chain length at RR_MAX_CE_ENTRIES = 32 but again left the block number unchecked. With a crafted ISO mounted via udisks2 (desktop optical auto-mount) or via CAP_SYS_ADMIN mount, rs->cont_extent can therefore point at an out-of-range block or at blocks belonging to an adjacent filesystem on the same block device. sb_bread() on an out-of-range block returns NULL cleanly via the block layer EIO path, so there is no memory-safety violation. For in-range reads of adjacent- filesystem data, the CE buffer is parsed as Rock Ridge records and only the text of SL sub-records reaches userspace through readlink(), which makes the info-leak channel narrow and difficult to exploit; still, rejecting the malformed CE outright matches the rejection shape already present in the same function for cont_offset and cont_size. Add an ISOFS_SB(sb)->s_nzones bounds check to rock_continue() next to the existing offset/size rejection, printing the same corrupted-directory-entry notice.

Published Jun 8, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

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 0.5% (30-day exploitation probability)+7
  • 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
0.55%
ahead of 45% of scored CVEs · Oct 14, 2026
Affects
Linux
Linux and 1 more
CVSS base
8.2
High · 3 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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. 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.

VendorProductVersionsStatusSource
Linux Linux version b6d20edb6e7cedb4eedb9e0193d20dd488ebae84≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d and < ef048470c90bc8c1b8318bb2ce329da9ef64b9fe≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d and < a36d990f591320e9dd379ab30063ebfe91d47e1fversion 08313e26e06d4aa9ce1cbba1a8e359e9cab9ad56version 212c4d33ca83e2144064fe9c2911607fbed5386fversion 96e44adce250199ec9b2b928be66365779ff1b59version 1fe5620fcd6c2f0a4a927ee10c8e53196da392f3version fbce0d7dc8965c9fb8d411862040239d4a768c71
and 17 more version 8190393a88f2b0321263a54f2a9eb5a2aa43be7eversion 486aa789eadcf44ed87f972b209299c516454693≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d and < e69da8eeab74b4f4505024c38a17bce060fe7df8≥ 2.6.32.66 and < 2.6.33≥ 3.2.67 and < 3.3≥ 3.4.107 and < 3.5≥ 3.10.64 and < 3.11≥ 3.12.36 and < 3.13≥ 3.14.28 and < 3.15≥ 3.17.8 and < 3.18≥ 3.18.2 and < 3.19version 3.19≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d and < 22b36fa081f38ab397c7697f9d539211b51a0cfc≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d and < c9b37c8b73f6368e4750e5ccb0632c380b43c6e5≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d and < bf1bc673c587f5ef7e9c09b94aea7c5a7847d4d9≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d and < d582e12378bc1637f337622feef762f53c43fd57≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d and < 8356fb821016797f5677cbeee5ddc0d32a95b4be
Vulnerable CVE Program (cve.org) e CISA ADP
Linux Linux Kernel ≥ 3.2.67 and < 3.3≥ 2.6.32.66 and < 2.6.33≥ 3.4.107 and < 3.5≥ 3.10.64 and < 3.11≥ 3.12.36 and < 3.13≥ 3.14.28 and < 3.15≥ 3.17.8 and < 3.18≥ 3.18.2 and < 5.10.258
and 7 more ≥ 5.11 and < 5.15.209≥ 5.16 and < 6.1.175≥ 6.2 and < 6.6.140≥ 6.7 and < 6.12.88≥ 6.13 and < 6.18.30≥ 6.19 and < 7.0.7version 7.1-rc1
Vulnerable NIST National Vulnerability Database

Attack characteristics

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

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
None

Every base score collected

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

ScoreVersionSeverityExpl.ImpactScored by
8.2 CVSS 3.1 High 3.9 4.2 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
8.2 CVSS 3.1 High — — GitHub, Inc. via GitHub Security Advisories
8.2 CVSS 3.1 High — — Linux via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-401 · Missing Release of Memory after Effective Lifetime

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.55%

Detection

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

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · linux/linux
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 8.2
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVE published
    Jun 8, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 14, 2026 – Oct 15, 2026
  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

13 on the record

Elsewhere on this site

Linux
every CVE for this vendor
Memory corruption
same class
CWE-401
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-99999 ipv4: validate checksum_start before completing checksum 10h
  • CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 10h
  • CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
  • CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
  • CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
  • 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 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-2026-46303 is "isofs: validate Rock Ridge CE continuation extent against volume size", 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 8.2 describes technical severity. EPSS 0.55% 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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