Security Vulnerabilities
libssh2 through 1.11.1, fixed in commit a13bb6c, contains a missing bounds check vulnerability that allows a malicious SSH server to trigger an arbitrary-length heap out-of-bounds read and a free of an uninitialized pointer via the publickey subsystem. In libssh2_publickey_list_fetch(), the version 1 response parser reads a server-controlled comment_len value and advances the parse pointer without verifying sufficient bytes remain in the buffer, causing the out-of-bounds read to leak heap pointers from adjacent allocations defeating ASLR, followed by heap allocator state corruption when the error cleanup path frees an uninitialized pointer from a non-zeroed realloc() region.
CVSS Score
7.7
EPSS Score
0.003
Published
2026-07-24
libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packet_length smaller than the cipher's block size during Encrypt-then-MAC cipher negotiation. In the fullpacket() function in src/transport.c, the ETM path allocates a buffer of packet_length bytes but copies blocksize minus one bytes via memcpy, causing an overflow that on 32-bit glibc writes attacker-controlled bytes into an adjacent chunk's SIZE field, enabling tcache bin confusion, overlapping live objects, and function pointer overwrite during the session handshake before authentication.
CVSS Score
7.7
EPSS Score
0.003
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
octeontx2-pf: avoid double free of pool->stack on AQ init failure
otx2_pool_aq_init() frees pool->stack when mailbox sync or retry
allocation fails, but leaves the pointer unchanged. Later,
otx2_sq_aura_pool_init() unwinds the partial setup through
otx2_aura_pool_free(), which frees pool->stack again. The CN20K-specific
cn20k_pool_aq_init() implementation has the same bug in
its corresponding error path.
Set pool->stack to NULL immediately after the local free so the shared
cleanup path does not free the same stack again while cleaning up
partially initialized pool state.
The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still present in
v7.1-rc3.
Runtime validation was not performed because reproducing this path
requires OcteonTX2/CN20K hardware.
CVSS Score
7.0
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
powerpc/time: Remove redundant preempt_disable|enable() calls from arch_irq_work_raise()
A kernel panic is observed when handling machine check exceptions from
real mode.
BUG: Unable to handle kernel data access on read at 0xc00000006be21300
Oops: Kernel access of bad area, sig: 11 [#1]
MSR: 8000000000001003 <SF,ME,RI,LE> CR: 88222248 XER: 00000005
CFAR: c00000000003ffc4 DAR: c00000006be21300 DSISR: 40000000 IRQMASK: 0
NIP [c000000000029e40] arch_irq_work_raise+0x10/0x70
LR [c00000000003ffc8] machine_check_queue_event+0xa8/0x150
Call Trace:
[c0000000179d3c70] [c00000000003ff64] machine_check_queue_event+0x44/0x150
[c0000000179d3d30] [c0000000000084e0] machine_check_early_common+0x1f0/0x2c0
The crash occurs because arch_irq_work_raise() calls preempt_disable()
from machine check exception (MCE) handlers running in real mode. In
this context, accessing the preempt_count can fault, leading to the panic.
The preempt_disable()/preempt_enable() pair in arch_irq_work_raise()
was originally added by commit 0fe1ac48bef0 ("powerpc/perf_event: Fix
oops due to perf_event_do_pending call") to avoid races while raising
irq work from exception context.
Later, commit 471ba0e686cb ("irq_work: Do not raise an IPI when
queueing work on the local CPU") added preemption protection in
irq_work_queue() path, while commit 20b876918c06 ("irq_work: Use per
cpu atomics instead of regular atomics") added equivalent
protection in irq_work_queue_on() before reaching arch_irq_work_raise():
irq_work_queue() / irq_work_queue_on()
-> preempt_disable()
-> __irq_work_queue_local()
-> irq_work_raise()
-> arch_irq_work_raise()
As a result, callers other than mce_irq_work_raise() already execute
with preemption disabled, making the additional
preempt_disable()/preempt_enable() pair in arch_irq_work_raise()
redundant.
The arch_irq_work_raise() function executes in NMI context when called
from MCE handler. Hence we will not be preempted or scheduled out since
we are in NMI context with MSR[EE]=0. Therefore, it is safe to remove
the preempt_disable()/preempt_enable() calls from here.
Remove it to avoid accessing preempt_count from real mode context.
[Maddy: Fixed the commit title]
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/a6xx: Check kzalloc return in a8xx_hfi_send_perf_table
Check the return value of kzalloc() to prevent a NULL pointer
dereference on allocation failure.
Patchwork: https://patchwork.freedesktop.org/patch/721342/
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages()
netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it
is wanting to unlock and compares that to rreq->no_unlock_folio so that it
doesn't unlock a folio being read for netfs_perform_write() or
netfs_write_begin().
However, given that netfs_unlock_abandoned_read_pages() is called _after_
NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to
dereference is the one specified by ->no_unlock_folio as ownership
immediately reverts to the caller.
Fix this by storing the folio pointer instead and using that rather than
the index. Also fix netfs_unlock_read_folio() where the same applies.
CVSS Score
9.8
EPSS Score
0.004
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix overrun check in netfs_extract_user_iter()
Fix netfs_extract_user_iter() so that if iov_iter_extract_pages() overfills
pages[], then those pages don't get included in the iterator constructed at
the end of the function. If there was an overfill, memory corruption has
already happened.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: bla: fix report_work leak on backbone_gw purge
batadv_bla_purge_backbone_gw() removes stale backbone gateway entries,
but fails to properly handle their associated report_work:
- If report_work is running, the purge must wait for it to finish before
freeing the backbone_gw, otherwise the worker may access freed memory
(e.g. bat_priv).
- If report_work is pending, the purge must cancel it and release the
reference held for that pending work item.
The previous implementation called hlist_for_each_entry_safe() inside a
spin_lock_bh() section, but cancel_work_sync() may sleep and therefore
cannot be called from within a spinlock-protected region.
Restructure the loop to handle one entry per spinlock critical section:
acquire the lock, find the next entry to purge, remove it from the hash
list, then release the lock before calling cancel_work_sync() and
dropping the hash_entry reference. Repeat until no more entries require
purging.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async
[Why&How]
dc_process_dmub_aux_transfer_async() copies payload->length bytes into a
16-byte stack buffer (dpaux.data[16]) guarded only by an ASSERT(), which
is a no-op in release builds. If a caller ever passes length > 16 this
results in a stack buffer overflow via memcpy.
Additionally, link_index is used to dereference dc->links[] without
bounds checking against dc->link_count, risking an out-of-bounds access.
Replace the ASSERT with a hard runtime check that returns false when
payload->length exceeds the destination buffer size, and add a bounds
check for link_index before it is used.
(cherry picked from commit ba4caa9fecdf7a38f98c878ad05a8a64148b6881)
CVSS Score
7.0
EPSS Score
0.001
Published
2026-07-24
In the Linux kernel, the following vulnerability has been resolved:
device property: set fwnode->secondary to NULL in fwnode_init()
If a firmware node is allocated on the stack (for instance: temporary
software node whose life-time we control) or on the heap - but using a
non-zeroing allocation function - and initialized using fwnode_init(),
its secondary pointer will contain uninitalized memory which likely will
be neither NULL nor IS_ERR() and so may end up being dereferenced (for
example: in dev_to_swnode()). Set fwnode->secondary to NULL on
initialization.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-24