Vulnerability in Linux kernel (CVE-2026-46303)
Summary
Vulnerability in Linux kernel (CVE-2026-46303). Confidential information can be exposed externally.
Original description
The description as published by the source.
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 exist…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-46303 has been found in Linux kernel.
Confidential information can be exposed externally. CVSS score: 8.2/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-46303" on the vendor's site.
CVE-2026-46303 (Linux kernel) — CWE-401 / CVSS v3 8.2
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-401) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: High (CVSS 8.2/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-46303 linux-lts Fixed in: 6.1.175-r0
- Debian DEBIAN-CVE-2026-46303 linux
- Ubuntu UBUNTU-CVE-2026-46303 linux
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com
- web cert-portal.siemens.com
- web cert-portal.siemens.com
- web cert-portal.siemens.com