CVE-2026-46300
Published: May 23, 2026· Updated: May 26, 2026
Official Description
In the Linux kernel, the following vulnerability has been resolved:
net: skbuff: preserve shared-frag marker during coalescing
skb_try_coalesce() can attach paged frags from @from to @to. If @from
has SKBFL_SHARED_FRAG set, the resulting @to skb can contain the same
externally-owned or page-cache-backed frags, but the shared-frag marker
is currently lost.
That breaks the invariant relied on by later in-place writers. In
particular, ESP input checks skb_has_shared_frag() before deciding
whether an uncloned nonlinear skb can skip skb_cow_data(). If TCP
receive coalescing has moved shared frags into an unmarked skb, ESP can
see skb_has_shared_frag() as false and decrypt in place over page-cache
backed frags.
Propagate SKBFL_SHARED_FRAG when skb_try_coalesce() transfers paged
frags. The tailroom copy path does not need the marker because it copies
bytes into @to's linear data rather than transferring frag descriptors.
Technical Analysis
CVE-2026-46300 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.8.
A proof-of-concept (PoC) exploit exists for CVE-2026-46300. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
News & Research Mentioning CVE-2026-46300
View CSAF Summary B&R is aware of publicly reported vulnerabilities affecting the Linux kernel versions shipped with the products listed as affected in the advisory. Successful local exploitation of these vulnerabilities could allow an attacker to escalate privileges on the affected system. Public proof-of-concept exploits are available for the vulnerabilities described herein. At the time of publication of this advisory, B&R had no evidence of active exploitation targeting B&R products. The following versions of Impact of Linux Kernel vulnerabilities on B&R products are affected: Linux for B&R /etc/modprobe.d/disable-algif.conf rmmod algif_aead 2>/dev/null || true Impact assessment: Disabling the algif_aead module removes the AEAD socket interface f [xlite_meta score:73 src:CISA Alerts xlite_fp:968f2d14c6ec3bfdadee07587780c6e8463e784ec0d508add5363b4e4f849d1f]
The vulnerability, tracked as CVE-2026-46300, is similar to the recently disclosed exploits named Dirty Frag and Copy Fail. The post New Linux Kernel Vulnerability Fragnesia Allows Root Privilege Escalation appeared first on SecurityWeek. [xlite_meta score:50 src:SecurityWeek xlite_fp:3e512662b971270d51f1d181a7a6bf871b696b43d5566adc499364a85fc1febe]
Linux distros are rolling out patches for a new high-severity kernel privilege escalation vulnerability (known as Fragnasia and tracked as CVE-2026-46300) that allows attackers to run malicious code as root. [...] [xlite_meta score:58 src:BleepingComputer xlite_fp:ed89ba4d41a983e8ca914b4bb0f87efa9edf2856ab73f8fe76639ec2818aeaef]
Details have emerged about a new variant of the recent Dirty Frag Linux local privilege escalation (LPE) vulnerability that allows local attackers to gain root access, making it the third such bug to be identified in the kernel within a span of two weeks. Codenamed Fragnesia, the security vulnerability is tracked as CVE-2026-46300 (CVSS score: 7.8) and is rooted in the Linux kernel's XFRM [xlite_meta score:50 src:The Hacker News xlite_fp:43328ffcf5f454e4f3688dc757ee3dbe67316410786a477e26c74816a63e4759]
All References (12)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-46300 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts