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

Status: published. Published: 2026-06-08. Updated: 2026-11-10.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d; < 8356fb821016797f5677cbeee5ddc0d32a95b4be (affected, git); ≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d; < d582e12378bc1637f337622feef762f53c43fd57 (affected, git); ≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d; < bf1bc673c587f5ef7e9c09b94aea7c5a7847d4d9 (affected, git); ≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d; < c9b37c8b73f6368e4750e5ccb0632c380b43c6e5 (affected, git); ≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d; < 22b36fa081f38ab397c7697f9d539211b51a0cfc (affected, git); ≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d; < e69da8eeab74b4f4505024c38a17bce060fe7df8 (affected, git); ≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d; < ef048470c90bc8c1b8318bb2ce329da9ef64b9fe (affected, git); ≥ f54e18f1b831c92f6512d2eedb224cd63d607d3d; < a36d990f591320e9dd379ab30063ebfe91d47e1f (affected, git); 08313e26e06d4aa9ce1cbba1a8e359e9cab9ad56 (affected, git); 212c4d33ca83e2144064fe9c2911607fbed5386f (affected, git); 96e44adce250199ec9b2b928be66365779ff1b59 (affected, git); 1fe5620fcd6c2f0a4a927ee10c8e53196da392f3 (affected, git); fbce0d7dc8965c9fb8d411862040239d4a768c71 (affected, git); 8190393a88f2b0321263a54f2a9eb5a2aa43be7e (affected, git); 486aa789eadcf44ed87f972b209299c516454693 (affected, git); b6d20edb6e7cedb4eedb9e0193d20dd488ebae84 (affected, git); ≥ 2.6.32.66; < 2.6.33 (affected, semver); ≥ 3.2.67; < 3.3 (affected, semver); ≥ 3.4.107; < 3.5 (affected, semver); ≥ 3.10.64; < 3.11 (affected, semver); ≥ 3.12.36; < 3.13 (affected, semver); ≥ 3.14.28; < 3.15 (affected, semver); ≥ 3.17.8; < 3.18 (affected, semver); ≥ 3.18.2; < 3.19 (affected, semver). Source: CNA: Linux
- Linux / Linux: 3.19 (affected); ≥ 0; < 3.19 (unaffected, semver); ≥ 5.10.258; ≤ 5.10.* (unaffected, semver); ≥ 5.15.209; ≤ 5.15.* (unaffected, semver); ≥ 6.1.175; ≤ 6.1.* (unaffected, semver); ≥ 6.6.140; ≤ 6.6.* (unaffected, semver); ≥ 6.12.88; ≤ 6.12.* (unaffected, semver); ≥ 6.18.30; ≤ 6.18.* (unaffected, semver); ≥ 7.0.7; ≤ 7.0.* (unaffected, semver); ≥ 7.1; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux
- Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0): ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0): ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0): ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0): ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0): ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0): ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0): ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0): ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 TM MFP - GNU/Linux subsystem: ≥ 0; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0): ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0): ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP

## Severity and prioritization

- CVSS 3.1: 8.2 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N; source: CNA: Linux

- CISA KEV: No listing in collected sources

- EPSS: 0.32% as of 2026-11-09; percentile 25.21%

- SSVC: Not available

- Weaknesses: Not reported

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://git.kernel.org/stable/c/8356fb821016797f5677cbeee5ddc0d32a95b4be (CNA: Linux)

- https://git.kernel.org/stable/c/d582e12378bc1637f337622feef762f53c43fd57 (CNA: Linux)

- https://git.kernel.org/stable/c/bf1bc673c587f5ef7e9c09b94aea7c5a7847d4d9 (CNA: Linux)

- https://git.kernel.org/stable/c/c9b37c8b73f6368e4750e5ccb0632c380b43c6e5 (CNA: Linux)

- https://git.kernel.org/stable/c/22b36fa081f38ab397c7697f9d539211b51a0cfc (CNA: Linux)

- https://git.kernel.org/stable/c/e69da8eeab74b4f4505024c38a17bce060fe7df8 (CNA: Linux)

- https://git.kernel.org/stable/c/ef048470c90bc8c1b8318bb2ce329da9ef64b9fe (CNA: Linux)

- https://git.kernel.org/stable/c/a36d990f591320e9dd379ab30063ebfe91d47e1f (CNA: Linux)

- https://cert-portal.siemens.com/productcert/html/ssa-019113.html (ADP: siemens-SADP)

- https://cert-portal.siemens.com/productcert/html/ssa-457936.html (ADP: siemens-SADP)

- https://cert-portal.siemens.com/productcert/html/ssa-784472.html (ADP: siemens-SADP)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2026-46303; retrieved 2026-11-10; source updated 2026-11-10

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-46303; retrieved 2026-11-10; source updated Not reported

Revision: ba623ff6c1ff16572295aa7f31a0cb1b0ae204d74f8dce37e788647b889acfaa

Canonical: https://y2.dev/cve/CVE-2026-46303

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