CVE-2026-68478: memstick: ms_block: reject a card that reports too many blocks
Vulnerability summary
CVE-2026-68478 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12.5% of scored vulnerabilities.
No CVSS vector published; no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 16 · Related 15Timeline
- 15-08-2026PublishedVulnerability first disclosed.
- 17-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: memstick: ms_block: reject a card that reports too many blocks msb_ftl_initialize() computes the zone count from the card block count with no bound: msb->zone_count = msb->block_count / MS_BLOCKS_IN_ZONE; ... for (i = 0; i < msb->zone_count; i++) msb->free_block_count[i] = MS_BLOCKS_IN_ZONE; msb->block_count is a card value. msb_read_boot_blocks() reads number_of_blocks from the card boot page and byte swaps it. free_block_count is a fixed int[MS_MAX_ZONES]. MS_MAX_ZONES is 16, so the valid indices are 0 to 15. The init loop above indexes it by zone_count. msb_mark_block_used() and msb_mark_block_unused() index it by pba / MS_BLOCKS_IN_ZONE, for pba up to block_count - 1. A card may report up to 65535 blocks. A block_count above 8192 (MS_MAX_ZONES * MS_BLOCKS_IN_ZONE) lets the pba index reach 16. That writes past free_block_count[] and corrupts struct msb_data. A larger count runs the init loop past the end too. A real Memory Stick has at most 16 zones. So it has at most 8192 blocks. msb_ftl_initialize() now rejects a card that reports more than MS_MAX_ZONES * MS_BLOCKS_IN_ZONE blocks.
CVSS metrics
Risk metrics not yet published.
EPSS trend
Probability
0.22%
Chance of exploitation in the next 30 days
Percentile
13%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.22% on 06-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: not stated in public data.
Ubuntu169 products
- linuxAll versions (No fix recorded) | < 5.15.0-198.208 | < 6.8.0-147.147 | < 7.0.0-38.38
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1117.124 | < 6.8.0-1067.70 | < 7.0.0-1014.14
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian1 product
- linux< 6.1.180-1 | < 6.12.100-1 | < 7.1.5-1
Linux1 product
- linux≥ 0ab30494bc4f3bc1ea4659b7c5d97c5218554a63, < a4b9961efe8640f50800811b4a2b2046b3dc2ccc | ≥ 0ab30494bc4f3bc1ea4659b7c5d97c5218554a63, < 8937b11f1c3896e066c3fb07387ba17bc8c50b8a | ≥ 0ab30494bc4f3bc1ea4659b7c5d97c5218554a63, < f1c675ecf6e5ad02722f0019f729d8bb588d502e | ≥ 0ab30494bc4f3bc1ea4659b7c5d97c5218554a63, < d5db3439ee8d1c165a09a47e984c4ba508c130df | ≥ 0ab30494bc4f3bc1ea4659b7c5d97c5218554a63, < b86666ac4009a252501cc17242582a7ec9ed976e | ≥ 0ab30494bc4f3bc1ea4659b7c5d97c5218554a63, < 39151f0708c84221e94cdd6aa070aba5d7cb1c01 | ≥ 0ab30494bc4f3bc1ea4659b7c5d97c5218554a63, < 47f0c7d856c67c9935546d2644f18c0d0131b449 | ≥ 0ab30494bc4f3bc1ea4659b7c5d97c5218554a63, < 718178f524b98bc920d74bc771aed823c8b81425 | 3.12
3 vendors · 171 products
