CVE-2026-43112: fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath
Vulnerability summary
CVE-2026-43112 is a high (CVSS 8.8) Out-of-bounds Read vulnerability in linux. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 28.9% of scored vulnerabilities.
Not severe (CVSS 8.8, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 51 · Related 38Timeline
- 06-05-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath When cifs_sanitize_prepath is called with an empty string or a string containing only delimiters (e.g., "/"), the current logic attempts to check *(cursor2 - 1) before cursor2 has advanced. This results in an out-of-bounds read. This patch adds an early exit check after stripping prepended delimiters. If no path content remains, the function returns NULL. The bug was identified via manual audit and verified using a standalone test case compiled with AddressSanitizer, which triggered a SEGV on affected inputs.
CVSS metrics
6 scores · 6 sources · 1 version- OSV · Red hatEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HDiffers
- OSV · UbuntuEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HDiffers
- OSV · DebianEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · ChainguardEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- NVDNIST8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.35%
Chance of exploitation in the next 30 days
Percentile
29%
Versus all other CVEs
30-day change
Decrease -0.33 pp
From 0.68% on 04-10-2026
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 causeAffected systems
Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu145 products
- linux< 5.15.0-186.196 | < 6.8.0-136.136 | All versions (No fix recorded)
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.15.0-1112.119 | < 6.8.0-1061.64 | All versions (No fix recorded)
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Redhat46 products
- bpftool< 0:4.18.0-553.141.1.el8_10
- bpftool-debuginfo< 0:4.18.0-553.141.1.el8_10
- kernel< 0:4.18.0-553.141.1.el8_10
- kernel-abi-stablelists< 0:4.18.0-553.141.1.el8_10
- kernel-core< 0:4.18.0-553.141.1.el8_10
Chainguard6 products
- linux-aws-6.18< 6.18.31-r0
- linux-azure-6.18< 6.18.24-r1
- linux-gcp-6.18< 6.18.31-r0
- linux-qemu-6.18< 6.18.31-r0
- linux-qemu-6.18-bootc-boot-installed< 6.18.31-r0
Linux2 products
- linux≥ c63433a09d6ae4c226fcbc66da4c58fc189fd746, < a2ba20c17de8eb028f96b1d85f119d3d25655bd9 | ≥ a31080899d5fdafcccf7f39dd214a814a2c82626, < fbced33599653471b4581dfe1abc7b467031f126 | ≥ a31080899d5fdafcccf7f39dd214a814a2c82626, < 5d4fe469fe7dbff7d874c196bb680a82f2625d95 | ≥ a31080899d5fdafcccf7f39dd214a814a2c82626, < 2d29214448ec0f4e7e18bb1c14dd4a6c07f1c439 | ≥ a31080899d5fdafcccf7f39dd214a814a2c82626, < 86f9c23e0814cfdffda9eedf0c591c51ba209010 | ≥ a31080899d5fdafcccf7f39dd214a814a2c82626, < 49b1ce6d7cfb6c5a49f68bf5ccfcfb6ba14e63c3 | ≥ a31080899d5fdafcccf7f39dd214a814a2c82626, < 78ec5bf2f589ec7fd8f169394bfeca541b077317 | ≥ 5.15.11, < 5.15.209 | 5.16
- linux_kernelEOL≥ 5.16.1, < 6.6.136 | ≥ 6.7, < 6.12.83 | ≥ 6.13, < 6.18.24 | ≥ 6.19, < 6.19.14 | 5.16 | 5.16:rc6 | 5.16:rc7 | 5.16:rc8 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6
Debian1 product
- linux< 6.1.176-1 | < 6.12.85-1 | < 6.19.14-1
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