CVE-2026-80995: linux
Vulnerability summary
CVE-2026-80995 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 5.4% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 11-09-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: net: mctp: hold a reference to the route device in mctp_route_lookup() mctp_route_lookup() uses rt->dev without holding a reference on it. mctp_route_lookup_single() returns the route under RCU only, so the route's device can be torn down concurrently: mctp_dev_put() drops the last reference and synchronously kfree()s mdev->addrs. mctp_dev_saddr() then reads rt->dev->addrs[0], giving a use-after-free reachable by an unprivileged local AF_MCTP user on the receive/forwarding path (no CAP_NET_RAW required): BUG: KASAN: slab-use-after-free in mctp_route_lookup Read of size 1 at addr ... by task mctp_uaf/... mctp_route_lookup mctp_pkttype_receive Freed by task ...: kfree mctp_dev_put mctp_dev_notify In the same window mctp_dst_from_route() -> mctp_dev_hold() also increments a refcount that has already reached zero ("refcount_t: addition on 0 ... mctp_dev_hold"). This reintroduces the use-after-free class of CVE-2023-3439: the source address lookup was moved ahead of the point where the destination takes its device reference. Take a reference with refcount_inc_not_zero() before touching rt->dev, skip a device that is already dead, and drop the reference once the destination has taken its own.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.17%
Chance of exploitation in the next 30 days
Percentile
5%
Versus all other CVEs
30-day change
+0.05 pp
From 0.12% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu102 products
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
- linux-aws-5.13All versions (No fix recorded)
- linux-aws-5.19All versions (No fix recorded)
Debian1 product
- linux< 7.2.6-1
Linux1 product
- linux≥ 22cb45afd221b9e4f2a1dcc74a8ff645b7293aa1, < cc561f8af25586300c2f9d285babb163b866b293 | ≥ 22cb45afd221b9e4f2a1dcc74a8ff645b7293aa1, < 408da1df18116c971c3392e21e50586688cd3fbf | 7.1
3 vendors · 104 products