CVE-2026-46130 | dm-verity-fec: fix reading parity bytes split across blocks (take 3)

In the Linux kernel, the following vulnerability has been resolved: dm-verity-fec: fix reading parity bytes split across blocks (take 3) fec_decode_bufs() assumes that the parity bytes of the first RS codeword it decodes are never split across parity blocks. This assumption is false. Consider v->fec->block_size == 4096 && v->fec->roots == 17 && fio->nbufs == 1, for example. In that case, each call to fec_decode_bufs() consumes v->fec->roots * (fio->nbufs << DM_VERITY_FEC_BUF_RS_BITS) = 272 parity bytes. Considering that the parity data for each message block starts on a block boundary, the byte alignment in the parity data will iterate through 272*i mod 4096 until the 3 parity blocks have been consumed. On the 16th call (i=15), the alignment will be 4080 bytes into the first block. Only 16 bytes remain in that block, but 17 parity bytes will be needed. The code reads out-of-bounds from the parity block buffer. Fortunately this doesn't normally happen, since it can occur only for certain non-default values of fec_roots *and* when the maximum number of buffers couldn't be allocated due to low memory. For example with block_size=4096 only the following cases are affected: fec_roots=17: nbufs in [1, 3, 5, 15] fec_roots=19: nbufs in [1, 229] fec_roots=21: nbufs in [1, 3, 5, 13, 15, 39, 65, 195] fec_roots=23: nbufs in [1, 89] Regardless, fix it by refactoring how the parity blocks are read.

Published: 2026-05-28 Last update: 2026-05-28 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2026-46130 is rated Low Risk (5.3/100): low exploitation likelihood (EPSS 0.02%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-46130

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-28 0.02%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-46130

CVSS metrics for this CVE.

No CVSS data in dataset for this CVE.

Weakness enumeration for CVE-2026-46130

GitHub Security Advisory for CVE-2026-46130

GHSA-6hvc-rwfc-mp4j · Severity: unknown — In the Linux kernel, the following vulnerability has been resolved: dm-verity-fec: fix reading...

OS Trackers for CVE-2026-46130

vendor priority summary link
debian unimportant CVE-2026-46130 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. https://security-tracker.debian.org/tracker/CVE-2026-46130
redhat medium https://access.redhat.com/security/cve/CVE-2026-46130
suse medium CVE-2026-46130 severity moderate: SUSE including 23 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 129 product×package rows across 25 product lines (SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS, … (25 product lines)): Known Not Affected 125, Fixed 4. https://www.suse.com/security/cve/CVE-2026-46130/
ubuntu medium CVE-2026-46130 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1422 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1024, ignored 169, released 84, not-affected 79, needed 66. https://ubuntu.com/security/CVE-2026-46130

Affected software / configurations for CVE-2026-46130

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-46130

cvelogic Threat Intelligence