CVE-2026-74222
Canonical Ubuntu Linux: use-after-free can lead to denial of service
- Risk score
- 64/100
- CVSS
- 8.2 v3.1
- Exploit chance (30 days)
- 0.3%
- Published
- 29 Sep 2026
Open in the live forecast Today's forecast
What to know
- What it is
- U-Boot before 2026.10-rc5 contains a use-after-free vulnerability in the httpc_recv_cb() function within the lwIP wget implementation. When HTTP data storage fails, the callback frees the connection PCB but returns ERR_BUF instead of ERR_ABRT, causing the TCP input path to access released memory and crash the bootload…
- Affected
- Canonical Ubuntu Linux before 2026.10
- Fix
- Upgrade Canonical Ubuntu Linux to 2026.10 or later.
- Exploitation
- No known exploitation
Story map
At a glance
Canonical Ubuntu Linux: Amber, patch this week. U-Boot before 2026.10-rc5 contains a buffer overflow in nfs_readlink_reply() function in net/nfs-common.c when processing NFS server responses. A malicious NFS server can send crafted READLINK replies with negative or oversized symlink length values to corrupt memory and crash the bootloader.
The flaws
- CVE-2026-74222: Use-after-free can lead to denial of service (CVSS 8.2 · EPSS 0%)
- CVE-2026-74221: Denial of service (CVSS 8.2 · EPSS 0%)
- CVE-2026-74220: Denial of service (CVSS 8.2 · EPSS 0%)
- CVE-2026-103262: Denial of service (CVSS 7.5 · EPSS 1%)
The fix
Upgrade Canonical Ubuntu Linux: 2026.10 · 6.5.9 or later on your release line
Who is exposed: Canonical Ubuntu Linux before 2026.10
Where it stands
- No known exploitation
How it unfolded
- 21 Oct, Ubuntu security notices (official): USN-8930-2: U-Boot vulnerabilities
- 22 Oct, Ubuntu security notices (official): USN-8952-1: Tornado vulnerabilities
Connects to
- Same weakness: Use-after-free (CWE-416). 399 other warnings in 30 days
- Same product: Earlier Canonical Ubuntu Linux warnings. 15 in the last 90 days
Why it is Amber
- CVSS 8.2 high
- Remotely exploitable without logging in
- Named in a government or vendor bulletin
Government and vendor bulletins
References
- https://ubuntu.com/security/notices/USN-8930-2
- https://github.com/u-boot/u-boot
- https://github.com/u-boot/u-boot/blob/v2026.07/net/lwip/wget.c#L194
- https://github.com/u-boot/u-boot/commit/2d94618a58aeb7630f18eee33419ce48d0fd3616
- https://www.vulncheck.com/advisories/u-boot-before-2026.10-rc5-use-after-free-in-lwip-wget-receive-callback
Original description
U-Boot before 2026.10-rc5 contains a use-after-free vulnerability in the httpc_recv_cb() function within the lwIP wget implementation. When HTTP data storage fails, the callback frees the connection PCB but returns ERR_BUF instead of ERR_ABRT, causing the TCP input path to access released memory and crash the bootloader.
Last activity 21 Oct 2026. Patch Forecast updates every hour.