Unknown

CVE-2026-93048 — mtd: part: reject MTDPART_OFS_RETAIN in mtd_add_partition()

In the Linux kernel, the following vulnerability has been resolved: mtd: part: reject MTDPART_OFS_RETAIN in mtd_add_partition() mtd_add_partition() does not reject the special offset value MTDPART_OFS_RETAIN (-3), which leads to a WARN_ON in add_mtd_device() when called through the BLKPG ioctl on NAND devices. The RETAIN value depends on cur_offset being the end of the previous partition, but in the dynamic partition path cur_offset equals the offset argument itself, causing undefined behavior. Commit 5daa7b21496a ("mtd: prepare partition add and del functions for ioctl requests") introduced mtd_add_partition() and correctly rejected MTDPART_OFS_APPEND (-1) and MTDPART_OFS_NXTBLK (-2), since those special offsets rely on cur_offset tracking the previous partition's end. However, commit 1a31368bf92e ("mtd: add a flags for partitions which should just leave smth. after them") later added MTDPART_OFS_RETAIN (-3) for the static partition table path without updating mtd_add_partition() to also reject this value. With offset=-3 passed via BLKPG, the RETAIN size calculation in allocate_partition() underflows (parent_size - 0xFFFFFFFFFFFFFFFD = parent_size + 3). If the underflow result does not appear to leave enough space, allocate_partition() jumps to out_register via goto, skipping erasesize initialization. This results in erasesize=0, which triggers: WARN_ON((!mtd->erasesize || !master->_erase) && !(mtd->flags & MTD_NO_ERASE)) in add_mtd_device(). If the underflow result appears to leave enough space, a bogus partition size is calculated, but the "out of reach" sanity check catches the invalid offset and creates a disabled empty partition (offset=0, size=0) instead of returning an error. Fix this by adding MTDPART_OFS_RETAIN to the rejection list in mtd_add_partition(), consistent with the existing handling of APPEND and NXTBLK.

Published Sep 17, 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

EPSS 0.2% (30-day exploitation probability)+2

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

0.21%

ahead of 11% of scored CVEs · Oct 16, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

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

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

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).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 1a31368bf92ef2a7da3ba379672c405bd2751df9 and < 701c3ae7273e1adc20db5d97c42e0139b479f16b≥ 1a31368bf92ef2a7da3ba379672c405bd2751df9 and < 6aaab2ace3f7b55733d904e5549acf8405f03642≥ 1a31368bf92ef2a7da3ba379672c405bd2751df9 and < 181c1bff940e7d3e34ca485d37e3cdbfe409203c≥ 1a31368bf92ef2a7da3ba379672c405bd2751df9 and < a536eb57be58442b19398b2783071007ecfb1735≥ 1a31368bf92ef2a7da3ba379672c405bd2751df9 and < e204e5c49a012f99638633fdbd773e3c86260053≥ 1a31368bf92ef2a7da3ba379672c405bd2751df9 and < 398aca2f90122d5abbabff1079deaeb885fe9e40≥ 1a31368bf92ef2a7da3ba379672c405bd2751df9 and < c645f6dd1af2ecc70fd3578e141f2f71fa9e4eff≥ 1a31368bf92ef2a7da3ba379672c405bd2751df9 and < b759d5bb6265419344ee9729fd0dc07ad85719d8 and 1 more version 3.2	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 16, 2026 · 2 reading(s) · max 0.21%

Detection

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

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 15, 2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 17, 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/6aaab2ace3f7b55733d904e5549acf8405f03642
NIST National Vulnerability Database
git.kernel.org/stable/c/181c1bff940e7d3e34ca485d37e3cdbfe409203c
NIST National Vulnerability Database
git.kernel.org/stable/c/c645f6dd1af2ecc70fd3578e141f2f71fa9e4eff
NIST National Vulnerability Database
git.kernel.org/stable/c/b759d5bb6265419344ee9729fd0dc07ad85719d8
NIST National Vulnerability Database
git.kernel.org/stable/c/e204e5c49a012f99638633fdbd773e3c86260053
NIST National Vulnerability Database
git.kernel.org/stable/c/701c3ae7273e1adc20db5d97c42e0139b479f16b
NIST National Vulnerability Database
git.kernel.org/stable/c/398aca2f90122d5abbabff1079deaeb885fe9e40
NIST National Vulnerability Database
git.kernel.org/stable/c/a536eb57be58442b19398b2783071007ecfb1735
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 2d
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 2d
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 3d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 3d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 3d
Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 3d

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 CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
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-2026-93048 is "mtd: part: reject MTDPART_OFS_RETAIN in mtd_add_partition()", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.21% 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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