CVE WatchJul 30, 2026

CVE-2025-71159

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free warning in btrfs_get_or_create_delayed_node()

CVSS

9.8

Critical

EPSS

0.2%

p11

KEV

—

Exploit Today

0-100

Published: Jan 23, 2026 · Last modified: Jul 30, 2026 · CWE-416

EPSS · 30d

0.1%EPSS · 30 days0.2%

2026-07-162026-08-13

Technical description

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free warning in btrfs_get_or_create_delayed_node() Previously, btrfs_get_or_create_delayed_node() set the delayed_node's refcount before acquiring the root->delayed_nodes lock. Commit e8513c012de7 ("btrfs: implement ref_tracker for delayed_nodes") moved refcount_set inside the critical section, which means there is no longer a memory barrier between setting the refcount and setting btrfs_inode->delayed_node. Without that barrier, the stores to node->refs and btrfs_inode->delayed_node may become visible out of order. Another thread can then read btrfs_inode->delayed_node and attempt to increment a refcount that hasn't been set yet, leading to a refcounting bug and a use-after-free warning. The fix is to move refcount_set back to where it was to take advantage of the implicit memory barrier provided by lock acquisition. Because the allocations now happen outside of the lock's critical section, they can use GFP_NOFS instead of GFP_ATOMIC.

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-119373.1 LOW

12.8%

——4IBM Security Verify Access 10.0 through 10.0.9.2 and IBM Verify Identity Access 11.0 through 11.0.3 and IBM Verify Identity Access Container 11.0 through 11.0.3 and IBM Security Verify Access Container 10.0 through 10.0.9.2 Reverse Proxy in certain configurations is vulnerable to a denial of service attack.2d CVE-2026-195485.5 MED

2.3%

——1Multiple Use-After-Free vulnerabilities were found in the add_archive_element function in ld/ldmain.c of the GNU linker (ld), a component of binutils. The root cause is that plugin_maybe_claim() in ld/plugin.c frees the original BFD object via bfd_close/_bfd_delete_bfd when entry->the_bfd->my_archive == NULL, but the caller retains both the original abfd parameter and a shallow copy (orig_input.the_bfd) as dangling pointers. These dangling pointers are subsequently dereferenced at three distinct locations in add_archive_element: 1. Line ~1442: accessing abfd->my_archive via bfd_usrdata(abfd->my_archive) 2. Line ~1493: multiple accesses to abfd and abfd->my_archive in a conditional check and bfd_get_filename call 3. Line ~1525: dereferencing the shallow copy orig_input.the_bfd->my_archive in trace/verbose logging The vulnerability is triggered when LTO plugins are active (link_info.lto_plugin_active is true) and the input object has abfd->my_archive == NULL, which is a valid state for standalone object files. Red Hat builds binutils with --enable-plugins and --enable-lto, confirming the vulnerable code path is compiled in and reachable. An attacker who can supply a crafted object or archive file to a build process using LTO-enabled linking could exploit this flaw to cause a denial of service (linker crash via segmentation fault). Arbitrary code execution is theoretically possible through heap manipulation but is substantially mitigated by hardening measures including stack protector, FORTIFY_SOURCE, ASLR, and PIE. The attack surface is limited to build-time environments — the linker is a development tool not exposed in production runtime. The most realistic exploitation scenario is a supply chain attack introducing a crafted object file as a build dependency in CI/CD pipelines or development environments.2d CVE-2026-195608.8 HIG

27.2%

——8Use after free in Blink in Google Chrome prior to 151.0.7922.137 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium security severity: High)2d CVE-2026-195598.8 HIG

27.2%

——8Use after free in HTML in Google Chrome prior to 151.0.7922.137 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium security severity: High)2d CVE-2026-195587.5 HIG

14.3%

——4Use after free in Extensions in Google Chrome prior to 151.0.7922.137 allowed an attacker who convinced a user to install a malicious extension to execute arbitrary code inside a sandbox via a crafted Chrome Extension. (Chromium security severity: High)2d CVE-2026-195578.3 HIG

18.4%

——6Use after free in TabStrip in Google Chrome on Mac prior to 151.0.7922.137 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: High)2d