CVE-2026-98127
Linux kernel: integer overflow
- Risk score
- 44/100
- CVSS
- 5.5 v3.1
- Exploit chance (30 days)
- 0.1%
- Published
- 25 Sep 2026
Open in the live forecast Today's forecast
What to know
- What it is
- In the Linux kernel, the following vulnerability has been resolved: smb/client: validate new EOF for insert range smb3_insert_range() does not check if the new file size (i_size + len) is valid. This allows FALLOC_FL_INSERT_RANGE to bypass RLIMIT_FSIZE, exceed s_maxbytes, or produce a size outside the loff_t range. Us…
- Affected
- Linux kernel
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Story map
At a glance
Linux kernel: Amber, patch this week. In the Linux kernel, the following vulnerability has been resolved: sctp: fix a TOCTOU race in SCTP_CMD_TIMER_START The SCTP_CMD_TIMER_START handler checks timer_pending() before calling timer_reduce(). The timer can expire and detach between these operations, causing timer_reduce() to rearm the timer without taking t…
The flaws
- CVE-2026-98127: Integer overflow (CVSS 5.5 · EPSS 0%)
- CVE-2026-98130: Race condition (CVSS 8.1 · EPSS 0%)
- CVE-2026-98115: Race condition (CVSS 8.8 · EPSS 0%)
- CVE-2026-98052: In the Linux kernel, the following vulnerability has been resolved: net: bcmasp: clear txcb->last… (CVSS 7.8 · EPSS 0%)
The fix
Fix: Apply the vendor's security update; see the linked advisory.
Who is exposed: Linux kernel
Where it stands
- No known exploitation
Connects to
- Same weakness: Integer overflow (CWE-190). 125 other warnings in 30 days
- Same product: Earlier Linux kernel warnings. 61 in the last 90 days
Why it is Yellow
- CVSS 5.5 medium
- On your watchlist: linux kernel
References
- https://git.kernel.org/stable/c/1519dc88c87f5346dae0464d7d6da1b6bf1f6e8e
- https://git.kernel.org/stable/c/7c2c69045aa76ccaa7f16f1478eb312130ce4951
- https://git.kernel.org/stable/c/b7f2e33d9f5db7b8e6e5e0a5a93d0c5e31870356
- https://git.kernel.org/stable/c/bc7602b9082ef195d913c4c16fa9853dd262333e
- https://git.kernel.org/stable/c/f8cbfe3a3fcee7d991fd223f660f3e5df13221cf
Original description
In the Linux kernel, the following vulnerability has been resolved: smb/client: validate new EOF for insert range smb3_insert_range() does not check if the new file size (i_size + len) is valid. This allows FALLOC_FL_INSERT_RANGE to bypass RLIMIT_FSIZE, exceed s_maxbytes, or produce a size outside the loff_t range. Use check_add_overflow() to calculate the new EOF. Validate it with inode_newsize_ok() before modifying the file. Reproducer, using a file on a CIFS mount: bash -c ' FILE=/mnt/cifs/repro trap "" SIGXFSZ ulimit -f 3072 # RLIMIT_FSIZE = 3 MiB # A regular write is stopped at 3 MiB. dd if=/dev/zero of="$FILE" bs=1M count=4 status=none stat -c "size after write: %s" "$FILE" # Insert 2 MiB into a 2 MiB file. truncate -s 2M "$FILE" fallocate -i -o 0 -l 2M "$FILE" stat -c "size after insert: %s" "$FILE" ' Before this change, the regular write stops at the 3 MiB limit, but insert range grows the file to 4 MiB: dd: error writing '/mnt/cifs/repro': File too large size after write: 3145728 size after insert: 4194304 After this change, insert range also fails at the limit and leaves the 2 MiB file unchanged: dd: error writing '/mnt/cifs/repro': File too large size after write: 3145728 fallocate: fallocate failed: File too large size after insert: 2097152
Last activity 25 Sep 2026. Patch Forecast updates every hour.