High severity · published May 8, 2026
CVE-2026-43284
xfrm: esp: avoid in-place decrypt on shared skb frags
8.8
CVSS
94.2%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: avoid in-place decrypt on shared skb frags MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(), so later paths that may modify packet data can first make a private copy. The IPv4/IPv6 datagram append paths did not set this flag when splicing pages into UDP skbs. That leaves an ESP-in-UDP packet made from shared pipe pages looking like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW fast path for uncloned skbs without a frag_list and decrypts in place over data that is not owned privately by the skb. Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching TCP. Also make ESP input fall back to skb_cow_data() when the flag is present, so ESP does not decrypt externally backed frags in place. Private nonlinear skb frags still use the existing fast path. This intentionally does not change ESP output. In esp_output_head(), the path that appends the ESP trailer to existing skb tailroom without calling skb_cow_data() is not reachable for nonlinear skbs: skb_tailroom() returns zero when skb->data_len is nonzero, while ESP tailen is positive. Thus ESP output will either use the separate destination-frag path or fall back to skb_cow_data().
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)94.2% · higher than 100% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
4.11 before 5.10.255; 5.12 before 5.15.205; 5.16 before 6.1.171; 6.2 before 6.6.138; 6.7 before 6.12.87; 6.13 before 6.18.28; +1 more · source: NVD
LI
Linux · Linux
cac2661c53f35cbe651bef9b07026a5a05ab8ce0 before a6cb440f274a22456ef3e86b457344f1678f38f9; cac2661c53f35cbe651bef9b07026a5a05ab8ce0 before ab8b995323e5237041472d07e5055f5f7dcdf15b; cac2661c53f35cbe651bef9b07026a5a05ab8ce0 before fe785bb3a8096dffcc4048a85cd0c83337eeecad; cac2661c53f35cbe651bef9b07026a5a05ab8ce0 before 5d55c7336f8032d434adcc5fab987ccc93a44aec; cac2661c53f35cbe651bef9b07026a5a05ab8ce0 before 8253aab4659ca16116b522203c2a6b18dccacea7; cac2661c53f35cbe651bef9b07026a5a05ab8ce0 before 50ed1e7873100f77abad20fd31c51029bc49cd03; +5 more · source: vendor
NF
NVIDIA for RHEL 10 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 10.0 Extended Update Support · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: CISA
In the news
VulnerabilityHigh
Hitachi Energy APM Edge Product
View CSAF Summary Hitachi Energy is aware of Dirty Frag vulnerabilities that affect APM Edge product versions listed in this document. Successful exploitation of these vulnerabilities could result in impact on confidentiality, integrity and availability of the product. Please refer to the Recommended Immediate Actions for information about the mitigation/remediation. The following versions of Hitachi Energy APM Edge Product are affected: APM Edge vers:APM_Edge/<=6.10 (CVE-2026-43284, CVE-2026-43500) CVSS Vendor Equipment Vulnerabilities v3 8.8 Hitachi Energy Hitachi Energy APM Edge Product Write-what-where Condition, Out-of-bounds Write Background Critical Infrastructure Sectors: Energy Countries/Areas Deployed: Worldwide Company Headquarters Location: Switzerland Vulnerabilities Expand All + CVE-2026-43284 CWE-123: Write-what-where Condition A vulnerability exists in the IPsec ESP subsystem (esp4, esp6) of the Linux kernel used in APM Edge that allows a local unprivileged user to escalate privileges to root. The flaw exists in how the kernel handles memory pages when processing ESP encrypted network packets. An attacker can craft a packet that causes the kernel to decrypt data directly into memory pages it does not own, including the cached copies of privileged operating system binaries. When one of those binaries is executed, the attacker's injected code runs with root privilege...
Aug 13, 2026·CISA Advisories
VulnerabilityHigh
Fragnesia: New Linux kernel LPE bug was spawned by Dirty Frag patch (CVE-2026-46300)
Researchers have found and disclosed yet another local privilege escalation (LPE) vulnerability in the Linux kernel: CVE-2026-46300, aka “Fragnesia”. The flaw is in the same class of vulnerabilities as the recently disclosed Dirty Frag bug(s). Like Dirty Frag, it affects the same Linux module (xfrm-ESP). In fact, according to Dirty Frag discoverer Hyunwoo Kim, Fragnesia was “accidentally activated” by the patch fixing one of the original Dirty Frag vulnerabilities (i.e., CVE-2026-43284). CVE-2026-46300 explained Fragnesia was … More → The post Fragnesia: New Linux kernel LPE bug was spawned by Dirty Frag patch (CVE-2026-46300) appeared first on Help Net Security .
May 14, 2026·Help Net Security
VulnerabilityCritical
Dirty Frag: Using the Page Caches as an Attack Surface
Dirty Frag is a Linux local privilege escalation (LPE) chain published on May 7, 2026. It combines two previously unknown kernel vulnerabilities can allow an unprivileged local user to escalate to root on many major Linux distributions. As of May 8, 2026, CVE-2026-43284 had been patched in mainline Linux, while public reporting indicated that CVE-2026-43500 […]
May 9, 2026·Qualys Blog
VulnerabilityHigh
Dirty Frag: Unpatched Linux vulnerability delivers root access
A week after Copy Fail, another Linux local privilege escalation vulnerability dubbed “Dirty Frag” has been revealed, along with a PoC exploit. What is Dirty Frag In effect, Dirty Frag refers to two flaws: A xfrm-ESP Page-Cache Write vulnerability (CVE-2026-43284, aka Copy Fail 2.0), now patched in the Linux kernel, affects the modules supporting one of the protocols used for IPsec A RxRPC Page-Cache Write vulnerability (CVE number reserved: CVE-2026-43500), currently unpatched, affects the modules … More → The post Dirty Frag: Unpatched Linux vulnerability delivers root access appeared first on Help Net Security .
May 8, 2026·Help Net Security