What is CVE-2026-31635?
In the Linux kernel, the following vulnerability has been resolved: rxrpc: fix oversized RESPONSE authenticator length check rxgk_verify_response() decodes auth_len from the packet and is supposed to verify that it fits in the remaining bytes. The existing check is inverted, so oversized RESPONSE authenticators are accepted and passed to rxgk_decrypt_skb(), which can later reach skb_to_sgvec() with an impossible length and hit BUG_ON(len). Decoded from the original latest-net reproduction logs with scripts/decode_stacktrace.sh: RIP: __skb_to_sgvec() [net/core/skbuff.c:5285 (discriminator 1)] Call Trace: skb_to_sgvec() [net/core/skbuff.c:5305] rxgk_decrypt_skb() [net/rxrpc/rxgk_common.h:81] rxgk_verify_response() [net/rxrpc/rxgk.c:1268] rxrpc_process_connection() [net/rxrpc/conn_event.c:266 net/rxrpc/conn_event.c:364 net/rxrpc/conn_event.c:386] process_one_work() [kernel/workqueue.c:3281] worker_thread() [kernel/workqueue.c:3353 kernel/workqueue.c:3440] kthread() [kernel/kthread.c:436] ret_from_fork() [arch/x86/kernel/process.c:164] Reject authenticator lengths that exceed the remaining packet payload.
The record classifies CVE-2026-31635 under weakness class CWE-130. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 187 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.5 — HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS (FIRST)
- 0.6% probability of exploitation in the next 30 days, higher than 48.6% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 7.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-04-24, last modified 2026-08-05
Is CVE-2026-31635 being exploited?
Weaponised exploit code for CVE-2026-31635 is publicly available. 4 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.
- 0xBlackash/CVE-2026-31635 (github)
- 0xFuffM3/CVE-2026-31635-DirtyDecrypt (github)
- Lutfifakee-Project/CVE-2026-31635 (github)
- trickest/cve (trickest)
Affected products and versions
- Linux: Kernel
How to fix CVE-2026-31635
The record marks a vendor fix as available for CVE-2026-31635. Patch reference: https://git.kernel.org/stable/c/e2f1a80d8b1ed6a5ae585a399c2b46500bdcc305. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2026-31635
2 tracked threats in the Threadlinqs corpus reference CVE-2026-31635, either in the campaign’s CVE list or as an indicator on the campaign record.
- Q2 2026 Vulnerability and Exploit Landscape: Exploited AI-platform flaws (OpenClaw CVE-2026-25253, Dify CVE-2026-41948, Open WebUI CVE-2026-45386), Exchange CVE-2026-45501, and Linux kernel page-cache LPE exploit wave (Copy Fail, Dirty Frag) — HIGH · 2026-10-20
- DirtyDecrypt / DirtyCBC — Linux Kernel rxgk Root LPE with Public PoC (CVE-2026-31635) — HIGH · 2026-05-18
Sources
Enriched from CVE.org, NVD, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.