Critical security advisoryCriticalFlagged by our vulnerability database: PHP2Shell is on CISA’s exploited list. Most WordPress hosting runs PHP. See if your site is affectedFlagged by our vulnerability database: PHP2Shell is being exploited. DetailsExploited: PHP2Shell. Check your site
HuttenlocherTechnologies
MediumCVSS 5.5Computers, phones & browsers

CVE-2025-21881

In the Linux kernel, the following vulnerability has been resolved: uprobes: Reject the shared zeropage in uprobe_write_opcode() We triggered the following cr

In the Linux kernel, the following vulnerability has been resolved: uprobes: Reject the shared zeropage in uprobe_write_opcode() We triggered the following crash in syzkaller tests: BUG: Bad page state in process syz.7.38 pfn:1eff3 page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1eff3 flags: 0x3fffff00004004(referenced|reserved|node=0|zone=1|lastcpupid=0x1fffff) raw: 003fffff00004004 ffffe6c6c07bfcc8 ffffe6c6c07bfcc8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000fffffffe 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x32/0x50 bad_page+0x69/0xf0 free_unref_page_prepare+0x401/0x500 free_unref_page+0x6d/0x1b0 uprobe_write_opcode+0x460/0x8e0 install_breakpoint.part.0+0x51/0x80 register_for_each_vma+0x1d9/0x2b0 __uprobe_register+0x245/0x300 bpf_uprobe_multi_link_attach+0x29b/0x4f0 link_create+0x1e2/0x280 __sys_bpf+0x75f/0xac0 __x64_sys_bpf+0x1a/0x30 do_syscall_64+0x56/0x100 entry_SYSCALL_64_after_hwframe+0x78/0xe2 BUG: Bad rss-coun

Description from the National Vulnerability Database, published by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

What to do: Apply the vendor’s update. The NVD record links to the advisory.

What it means for a small business

Linux is on the computers, phones or browsers your team uses every day. Turn on automatic updates and restart: most of these fixes only take effect after a restart.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.21%, higher than 10% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

  • Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
  • Server check: what your web server says about itself, and whether that version has known flaws.

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

Weekly security brief

The flaws that hit local websites, every Friday.

One short email: what got exploited this week, which WordPress plugins broke, and what to check. Unsubscribe in one click.

Get in touch

Tell us what you're building.

A website, your marketing, a security check, an app, or the thing you've been running out of a spreadsheet for three years. A few lines is plenty.

01The person who'll do the work writes back
02A short call, then a written plan with the price
03Nothing starts until you say yes
04Hacked or down right now? Call, and we pick up the same day
843-331-6339

Not ready to talk yet? Run the free website check and see what Google sees.

What do you need?
Build
Grow
Protect
Urgent

No newsletter, no sales sequence. Just a reply.