CVE-2026-99113 json
ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in
published 14d ago modified 12d ago also EUVD-2026-112013
- cvss
- —
- not scored
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 6%
- public exploits
- 0
- none known
Summary
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in
smb2_get_info_filesystem() reports 64 bytes for FS_OBJECT_ID_INFORMATION, that is the whole of struct object_id_info, but writes only 46 of them:
- objid[] is 16 bytes, and when the volume UUID is not available only sizeof(stfs.f_fsid) (8) bytes are copied into it; - extended_info.version_string[] is STRING_LENGTH (28) bytes, and only strlen("1.1.0") (5) bytes are copied into it.
The response buffer is zeroed on allocation (kvzalloc() in smb2_allocate_rsp_buf()), so for a standalone request the remaining 31 bytes are zero. In a compound request they need not be. The offset of the next response is advanced by the length pinned for the previous one, so if a preceding command wrote its reply into the buffer and then failed, smb2_set_err_rsp() pins only the short error response and the next reply lands inside the area that has already been written. Only the header is cleared there:
memset((char *)rsp_hdr, 0, sizeof(struct smb2_hdr) + 2);
The client then receives up to 31 bytes of a response it was not meant to see, including one that failed with an access denied error.
Clear the structure before filling it in. As a side effect version_string is now NUL terminated.
Patch / fix
- Linux Linux 7.3
- linux Debian 13 6.12.115-2
- linux Debian 14 7.2.13-1
debian advisories DEBIAN-CVE-2026-99113
- kernel Azure Linux 3.0 6.6.161.1-1
azure linux advisories AZL-111206
Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT
- git.kernel.org/stable/c/dbd0f13de153d7094b85034daffa7533d7c2b17a commit
- git.kernel.org/stable/c/90898571fb2c6813c007a62833dd65c00481d44e commit
- git.kernel.org/stable/c/1a35a81c302b36fe4acd35b47b51d5d73e89ba0a commit
- git.kernel.org/stable/c/3fc33ac2125b60f103592b83821f69f3f9aa23ba commit
- git.kernel.org/stable/c/898cb4f2e12a5ddea1b2d821cc642c3100f46da7 commit
- git.kernel.org/stable/c/015fffa48e96ca8d73a627445341ccff86b02251 commit
- git.kernel.org/stable/c/399aa12450a61a5c73dc77e73f069ece9687c95d commit
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Check with FencerVendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-99113 updated cvss 4.3
kernel: ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in
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Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9not affected: vulnerable code not present
+1 more productsfewer
Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-11).
Affected products
- Linux Linux
Classification
- Technology feeds
References
- git.kernel.org /stable/c/dbd0f13de153d7094b85034daffa7533d7c2b17a
- git.kernel.org /stable/c/90898571fb2c6813c007a62833dd65c00481d44e
- git.kernel.org /stable/c/1a35a81c302b36fe4acd35b47b51d5d73e89ba0a
- git.kernel.org /stable/c/3fc33ac2125b60f103592b83821f69f3f9aa23ba
- git.kernel.org /stable/c/898cb4f2e12a5ddea1b2d821cc642c3100f46da7
- git.kernel.org /stable/c/015fffa48e96ca8d73a627445341ccff86b02251
- git.kernel.org /stable/c/399aa12450a61a5c73dc77e73f069ece9687c95d
Sources
- CVE List CVE-2026-99113
- NVD CVE-2026-99113
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