CVE-2026-74222
HIGH 8.8U-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.
Severe if exploited (CVSS 8.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 22nd percentile
Impact if exploited
8.8CVSS 4.0 · HIGH
- ConfidentialityNone
- IntegrityLow
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
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Data snapshot:
Weakness (CWE)
- CWE-416: Use After Free
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
References and research data (JSON)
All CVSS metrics
- HIGH 8.8 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N - HIGH 8.2 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - HIGH 8.8 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - HIGH 8.2 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
References
Patches & mitigations
- https://github.com/u-boot/u-boot/commit/2d94618a58aeb7630f18eee33419ce48d0fd3616 CVE record · VulnCheck · Updated 2026-09-29T21:29:23.960Z
NVD · CVE-2026-74222 · Updated 2026-10-02T13:17:54.703
Advisories
- https://www.vulncheck.com/advisories/u-boot-before-2026.10-rc5-use-after-free-in-lwip-wget-receive-callback CVE record · VulnCheck · Updated 2026-09-29T21:29:23.960Z
NVD · CVE-2026-74222 · Updated 2026-10-02T13:17:54.703 - https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-89435 EUVD · EUVD-2026-89435
Technical & other
- https://github.com/u-boot/u-boot/blob/v2026.07/net/lwip/wget.c#L194 CVE record · VulnCheck · Updated 2026-09-29T21:29:23.960Z
NVD · CVE-2026-74222 · Updated 2026-10-02T13:17:54.703 - https://github.com/u-boot/u-boot CVE record · VulnCheck · Updated 2026-09-29T21:29:23.960Z
NVD · CVE-2026-74222 · Updated 2026-10-02T13:17:54.703