Use After Free
CWE-416
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
We track 4,465 vulnerabilities of this type. 100% are rated high or critical, and the average CVSS score is 8.3. 109 have been exploited in real attacks.
How this weakness is prevented
- Architecture and Design: Choose a language that provides automatic memory management.
- Implementation: When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Latest Use After Free vulnerabilities
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in durable v2 replay of active file handles parse_durable_handle_context() unconditionally assigns dh_info->fp->conn to the current connection when handling a DURABLE
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy() During futex_key_to_node_opt() execution, vma->vm_policy is read under speculative mmap lock and RCU. Concurrently, mbin
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: clsact: Fix use-after-free in init/destroy rollback asymmetry Fix a use-after-free in the clsact qdisc upon init/destroy rollback asymmetry. The latter is achieved by first fully initializing
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: netfilter: bpf: defer hook memory release until rcu readers are done Yiming Qian reports UaF when concurrent process is dumping hooks via nfnetlink_hooks: BUG: KASAN: slab-use-after-free in nf
- 9.6 Critical severity
Chrome: Use After Free
Use after free in Compositing in Google Chrome prior to 146.0.7680.178 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)
- 9.6 Critical severity
Chrome: Use After Free
Use after free in Navigation in Google Chrome prior to 146.0.7680.178 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)
- 9.6 Critical severity
Chrome: Use After Free
Use after free in WebView in Google Chrome on Android prior to 146.0.7680.178 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)
- 8.8 High severity
Chrome: Use After Free
Use after free in PDF in Google Chrome prior to 146.0.7680.178 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted PDF file. (Chromium security severity: High)
- 8.8 High severity
Chrome: Use After Free
Use after free in Dawn in Google Chrome prior to 146.0.7680.178 allowed a remote attacker to execute arbitrary code via a crafted HTML page. (Chromium security severity: High)
- 8.8 High severity
Chrome: Use After Free
Use after free in WebGL in Google Chrome prior to 146.0.7680.178 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium security severity: High)
- 7.5 High severity
Chrome: Use After Free
Use after free in Dawn in Google Chrome prior to 146.0.7680.178 allowed a remote attacker who had compromised the renderer process to execute arbitrary code via a crafted HTML page. (Chromium security severity: High)
- 8.8 High severity
Google Dawn Use-After-Free Exploited
Use after free in Dawn in Google Chrome prior to 146.0.7680.178 allowed a remote attacker who had compromised the renderer process to execute arbitrary code via a crafted HTML page. (Chromium security severity: High)
- 8.8 High severity
Chrome: Use After Free
Use after free in WebCodecs in Google Chrome prior to 146.0.7680.178 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium security severity: High)
- 8.8 High severity
Chrome: Use After Free
Use after free in Web MIDI in Google Chrome on Android prior to 146.0.7680.178 allowed a remote attacker to execute arbitrary code via a crafted HTML page. (Chromium security severity: High)
- 7.8 High severity
Foxit PDF Editor: Use After Free
The application's list box calculate array logic keeps stale references to page or form objects after they are deleted or re-created, which allows crafted documents to trigger a use-after-free when the calculation runs and can potentially lead to arbitrary cod
- 7.8 High severity
Foxit PDF Editor: Use After Free
The application does not properly validate the lifetime and validity of internal view cache pointers after JavaScript changes the document zoom and page state. When a script modifies the zoom property and then triggers a page change, the original view object m
- 7.5 High severity
DNSdist: Use After Free
An attacker might be able to trigger a use-after-free by sending crafted DNS queries to a DNSdist using the DNSQuestion:getEDNSOptions method in custom Lua code. In some cases DNSQuestion:getEDNSOptions might refer to a version of the DNS packet that has been
- 7.8 High severity
Substance3D - Stager: Use After Free
Substance3D - Stager versions 3.1.7 and earlier are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a m
- 7.5 High severity
libpng: Use After Free
LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. In versions 1.2.1 through 1.6.55, `png_set_tRNS` and `png_set_PLTE` each alias a heap-allocated buffer between `png_stru
- 7.5 High severity
everest-core: Use After Free
EVerest is an EV charging software stack. Prior to version 2026.02.0, ISO15118_chargerImpl::handle_session_setup uses v2g_ctx after it has been freed when ISO15118 initialization fails (e.g., no IPv6 link-local address). The EVSE process can be crashed remotel
- 7.5 High severity
squid: Use After Free
Squid is a caching proxy for the Web. Prior to version 7.5, due to heap Use-After-Free, Squid is vulnerable to Denial of Service when handling ICP traffic. This problem allows a remote attacker to perform a reliable and repeatable Denial of Service attack agai
- 7.5 High severity
squid: Improper Resource Locking
Squid is a caching proxy for the Web. Prior to version 7.5, due to premature release of resource during expected lifetime and heap Use-After-Free bugs, Squid is vulnerable to Denial of Service when handling ICP traffic. This problem allows a remote attacker to
- 7.8 High severity
cryptodev-linux: Use After Free
cryptodev-linux version 1.14 and prior contain a page reference handling flaw in the get_userbuf function of the /dev/crypto device driver that allows local users to trigger use-after-free conditions. Attackers with access to the /dev/crypto interface can repe
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: release flowtable after rcu grace period on error Call synchronize_rcu() after unregistering the hooks from error path, since a hook that already refers to this flowtable
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_CT: drop pending enqueued packets on template removal Templates refer to objects that can go away while packets are sitting in nfqueue refer to: - helper, this can be an issue on
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_set_pipapo: split gc into unlink and reclaim phase Yiming Qian reports Use-after-free in the pipapo set type: Under a large number of expired elements, commit-time GC can run fo
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: crypto: ccp - Fix use-after-free on error path In the error path of sev_tsm_init_locked(), the code dereferences 't' after it has been freed with kfree(). The pr_err() statement attempts to ac
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: net: sched: avoid qdisc_reset_all_tx_gt() vs dequeue race for lockless qdiscs When shrinking the number of real tx queues, netif_set_real_num_tx_queues() calls qdisc_reset_all_tx_gt() to flush
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: cancel rfkill_block work in wiphy_unregister() There is a use-after-free error in cfg80211_shutdown_all_interfaces found by syzkaller: BUG: KASAN: use-after-free in cfg80211_sh
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: ipmi: Fix use-after-free and list corruption on sender error The analysis from Breno: When the SMI sender returns an error, smi_work() delivers an error response but then jumps back to restart
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix a UAF issue in bpf_trampoline_link_cgroup_shim The root cause of this bug is that when 'bpf_link_put' reduces the refcount of 'shim_link->link.link' to zero, the resource is considere
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: scsi: pm8001: Fix use-after-free in pm8001_queue_command() Commit e29c47fe8946 ("scsi: pm8001: Simplify pm8001_task_exec()") refactors pm8001_queue_command(), however it introduces a potential
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: wifi: libertas: fix use-after-free in lbs_free_adapter() The lbs_free_adapter() function uses timer_delete() (non-synchronous) for both command_timer and tx_lockup_timer before the structure i
- 8.8 High severity
Safari: Out-of-bounds Read
The issue was addressed with improved memory handling. This issue is fixed in Safari 26.4, iOS 26.4 and iPadOS 26.4, macOS Tahoe 26.4, tvOS 26.4, visionOS 26.4, watchOS 26.4. A malicious website may be able to process restricted web content outside the sandbox
- 8.8 High severity
Safari: Out-of-bounds Read
The issue was addressed with improved memory handling. This issue is fixed in Safari 26.4, iOS 26.4 and iPadOS 26.4, macOS Tahoe 26.4, visionOS 26.4. Processing maliciously crafted web content may lead to an unexpected process crash.
- 7.1 High severity
iOS and iPadOS: Use After Free
A use after free issue was addressed with improved memory management. This issue is fixed in iOS 18.7.7 and iPadOS 18.7.7, iOS 26.4 and iPadOS 26.4, macOS Sequoia 15.7.5, macOS Tahoe 26.4, tvOS 26.4, watchOS 26.4. An app may be able to cause unexpected system
- 9.8 Critical severity
Firefox: Use After Free
Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 9.8 Critical severity
Firefox: Use After Free
Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 9.8 Critical severity
Firefox: Use After Free
Use-after-free in the Layout: Text and Fonts component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- 9.8 Critical severity
Firefox: Use After Free
Use-after-free in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.