---
cve: "CVE-2026-53078"
severity: "HIGH"
cvss: 7.8
epss: "12%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-06-24 17:17:21"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-10T11:44:45+02:00"
---

# CVE-2026-53078

> 7.8 HIGH

## Beschreibung

In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix same-register dst/src OOB read and pointer leak in sock_ops

When a BPF sock_ops program accesses ctx fields with dst_reg == src_reg,
the SOCK_OPS_GET_SK() and SOCK_OPS_GET_FIELD() macros fail to zero the
destination register in the !fullsock / !locked_tcp_sock path.

Both macros borrow a temporary register to check is_fullsock /
is_locked_tcp_sock when dst_reg == src_reg, because dst_reg holds the
ctx pointer. When the check is false (e.g., TCP_NEW_SYN_RECV state with
a request_sock), dst_reg should be zeroed but is not, leaving the stale
ctx pointer:

 - SOCK_OPS_GET_SK: dst_reg retains the ctx pointer, passes NULL checks
   as PTR_TO_SOCKET_OR_NULL, and can be used as a bogus socket pointer,
   leading to stack-out-of-bounds access in helpers like
   bpf_skc_to_tcp6_sock().

 - SOCK_OPS_GET_FIELD: dst_reg retains the ctx pointer which the
   verifier believes is a SCALAR_VALUE, leaking a kernel pointer.

Fix both macros by:
 - Changing JMP_A(1) to JMP_A(2) in the fullsock path to skip the
   added instruction.
 - Adding BPF_MOV64_IMM(si->dst_reg, 0) after the temp register
   restore in the !fullsock path, placed after the restore because
   dst_reg == src_reg means we need src_reg intact to read ctx->temp.

## CVSS-Vektor

```
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 6.12.101
- Kernel ≥ 6.18.42
- Kernel ≥ 7.0.10

## Referenzen

- <https://git.kernel.org/stable/c/2a2c98141e0a75f2d4a7d78b0316c88b3da784ac>
- <https://git.kernel.org/stable/c/22400725de070b787cd6d806c5795370ab46d269>
- <https://git.kernel.org/stable/c/18e3ffde1822f0b48b1753bf34aa97ce839df1d8>
- <https://git.kernel.org/stable/c/10f86a2a5c91fc4c4d001960f1c21abe52545ef6>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-53078) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_