U-Boot 2026.04-rc3 Integer Underflow DoS via tcp_rx_state_machine()
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| u-boot | u-boot | affected |
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Configuration 1 [-]
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No data.
| Vendor | Product | Versions | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| U-boot | U-boot |
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No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.706% probability within 30 days)
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Denx
Denx u-boot |
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| CPEs | cpe:2.3:a:denx:u-boot:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Denx
Denx u-boot |
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
U-boot
U-boot u-boot |
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| Vendors & Products |
U-boot
U-boot u-boot |
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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| Type | Values Removed | Values Added |
|---|---|---|
| Description | U-Boot through 2026.04-rc3 contains an integer underflow vulnerability in the tcp_rx_state_machine() function (net/tcp.c) that allows a network-adjacent attacker to crash the bootloader by sending a malformed TCP SYN+ACK packet with a manipulated data offset field causing payload_len to become negative. When the TCP_SYN_SENT handler calls tcp_rx_user_data() without invoking tcp_seg_in_wnd() validation, the negative payload_len is implicitly converted to a large unsigned integer (e.g., 0xFFFFFFD8) and passed to memcpy() in store_block(), causing an immediate crash that prevents device boot and may enable memory corruption when CONFIG_LMB is disabled. | |
| Title | U-Boot 2026.04-rc3 Integer Underflow DoS via tcp_rx_state_machine() | |
| Weaknesses | CWE-191 | |
| References |
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| Metrics |
cvssV3_1
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