[HIGH] CVE-2026-43500 — CVSS 7.8 (May 11, 2026)

A HIGH-severity vulnerability identified as CVE-2026-43500 has been published on May 11, 2026 with a CVSS base score of 7.8. The vulnerability affects Linux Linux kernel. This security advisory provides a detailed breakdown of the vulnerability, its potential impact, weakness classification, and actionable steps to protect your systems.

Vulnerability Details

CVE ID: CVE-2026-43500
Severity: HIGH
CVSS Score: 7.8
Published: May 11, 2026
Affected Product: Linux Linux kernel
Weakness (CWE): CWE-787

Technical Description

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE handler in rxrpc_verify_response() copy the skb to a linear one before calling into the security ops only when skb_cloned() is true. An skb that is not cloned but still carries externally-owned paged fragments (e.g. SKBFL_SHARED_FRAG set by splice() into a UDP socket via __ip_append_data, or a chained skb_has_frag_list()) falls through to the in-place decryption path, which binds the frag pages directly into the AEAD/skcipher SGL via skb_to_sgvec(). Extend the gate to also unshare when skb_has_frag_list() or skb_has_shared_frag() is true. This catches the splice-loopback vector and other externally-shared frag sources while preserving the zero-copy fast path for skbs whose frags are kernel-private (e.g. NIC page_pool RX, GRO). The OOM/trace handling already in place is reused.

Potential Impact

If exploited, this high-severity vulnerability could allow an attacker to compromise sensitive data confidentiality, tamper with system integrity, cause a denial of service. Organizations running Linux Linux kernel should treat this as a priority remediation item.

Recommended Action

A patch or vendor advisory is available. Take the following steps immediately:

1. Review the vendor advisory linked in the References section below.
2. Identify all instances of the affected software in your environment.
3. Apply the available patch or upgrade to the fixed version as soon as possible.
4. If patching is not immediately possible, implement compensating controls such as WAF rules, network segmentation, or disabling the affected feature.
5. Monitor your systems for signs of exploitation using your SIEM or IDS/IPS.

View full details on NVD →

References

• Patch
• Patch
• Patch
• Reference 4

Related Security Advisories

• [HIGH] CVE-2026-20416 — CVSS 7.2 (March 2, 2026) — HIGH / CVSS 7.2
• [HIGH] CVE-2026-3828 — CVSS 7.2 (May 9, 2026) — HIGH / CVSS 7.2
• [HIGH] CVE-2026-43284 — CVSS 7.8 (May 8, 2026) — HIGH / CVSS 7.8