CVE-2026-45998: rxrpc: Fix potential UAF after skb_unshare() failure
Vulnerability summary
CVE-2026-45998 is a high (CVSS 7.8) Use After Free vulnerability in linux. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 3.1% of scored vulnerabilities.
Not severe (CVSS 7, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 18 · Related 12Timeline
- 27-05-2026PublishedVulnerability first disclosed.
- 16-09-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix potential UAF after skb_unshare() failure If skb_unshare() fails to unshare a packet due to allocation failure in rxrpc_input_packet(), the skb pointer in the parent (rxrpc_io_thread()) will be NULL'd out. This will likely cause the call to trace_rxrpc_rx_done() to oops. Fix this by moving the unsharing down to where rxrpc_input_call_event() calls rxrpc_input_call_packet(). There are a number of places prior to that where we ignore DATA packets for a variety of reasons (such as the call already being complete) for which an unshare is then avoided. And with that, rxrpc_input_packet() doesn't need to take a pointer to the pointer to the packet, so change that to just a pointer.
CVSS metrics
4 scores · 4 sources · 1 version- CVE.orgCNA7.0HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HDiffers
- OSV · UbuntuEcosystem advisory · calculated7.0HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HDiffers
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.14%
Chance of exploitation in the next 30 days
Percentile
3%
Versus all other CVEs
30-day change
Decrease -0.05 pp
From 0.19% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
- CWE-825Expired Pointer DereferenceThe product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu132 products
- linux< 6.8.0-124.124 | < 6.17.0-35.35 | < 7.0.0-22.22
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1057.60 | < 6.17.0-1017.17 | < 7.0.0-1006.6
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 2d1faf7a0ca3c0b327cf064c80e4e775532c9319, < e3bf143b1e98fb3d6d9e6825bcd683974d478e8c | ≥ 2d1faf7a0ca3c0b327cf064c80e4e775532c9319, < bf20f46d94f1db38e6ffc0ca204a5fe0de01b495 | ≥ 2d1faf7a0ca3c0b327cf064c80e4e775532c9319, < 996b0487b3cdda4c91811dbb1c9564626bc840bd | ≥ 2d1faf7a0ca3c0b327cf064c80e4e775532c9319, < 8fde6296c4d4da2be7ab761305ab7f232b94eefd | ≥ 2d1faf7a0ca3c0b327cf064c80e4e775532c9319, < 1f2740150f904bfa60e4bad74d65add3ccb5e7f8 | 6.2
- linux_kernel≥ 6.2, < 6.6.140 | ≥ 6.7, < 6.12.86 | ≥ 6.13, < 6.18.27 | ≥ 6.19, < 7.0.4
Debian1 product
- linux< 6.12.86-1 | < 7.0.4-1
3 vendors · 135 products
