DEBIAN-CVE-2026-98122

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Source

https://security-tracker.debian.org/tracker/CVE-2026-98122

Import Source

https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-98122.json

JSON Data

https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-98122

Upstream

CVE-2026-98122

Published

2026-09-25T11:17:43Z

Modified

2026-09-26T05:01:35Z

Severity

7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator

Summary

[none]

Details

In the Linux kernel, the following vulnerability has been resolved: vxlan: mdb: Fix use-after-free in vxlan_mdb_remote_src_del() vxlan_mdb_is_valid_source(), which validates MDBE_ATTR_SOURCE and every MDBE_ATTR_SRC_LIST member, accepts the all-zeros address. A source list is only accepted on a (, G) entry, whose source is the all-zeros address, and for each member of the list an (S, G) entry is derived from it by substituting the source. Entries are keyed by a plain memcmp() of struct vxlan_mdb_entry_key, so if MDBE_ATTR_SOURCE is present and holds the all-zeros address and the source list holds it as well, the derived (S, G) key is byte-identical to the (, G) key and resolves to the same entry. Omitting MDBE_ATTR_SOURCE is not equivalent, as the key is then left with a zero address family. vxlan_mdb_remote_src_del() removes the forwarding entry of a source before freeing the source entry: vxlan_mdb_remote_src_fwd_del(vxlan, group, remote, &ent->addr); vxlan_mdb_remote_src_entry_del(ent); With the keys aliased, the first call deletes the remote of the entry that owns 'ent' instead of a separate (S, G) entry, and frees 'ent'. The second call then runs on the freed entry, and its hlist_del() reads ->pprev and ->next out of it and writes through them. Adding the (, G) entry with NLM_F_REPLACE and no source list marks the all-zeros source for deletion and reaches this from the sweep at the end of vxlan_mdb_remote_srcs_replace(). BUG: KASAN: slab-use-after-free in __vxlan_mdb_add+0x1cd/0xd70 Read of size 8 at addr ffff888102852500 by task poc/84 __vxlan_mdb_add+0x1cd/0xd70 vxlan_mdb_add+0xc0/0x140 rtnl_mdb_add+0x157/0x2a0 rtnetlink_rcv_msg+0x207/0x5a0 Allocated by task 84: __kmalloc_cache_noprof+0x153/0x360 vxlan_mdb_remote_srcs_add+0x2eb/0x440 __vxlan_mdb_add+0x803/0xd70 Freed by task 84: kfree+0x14c/0x3b0 vxlan_mdb_remote_del+0x129/0x1a0 __vxlan_mdb_del+0x4f/0xe0 vxlan_mdb_remote_src_fwd_del.isra.0+0x162/0x1b0 __vxlan_mdb_add+0x1c5/0xd70 The MDB operations are netns-scoped, so an unprivileged user can perform them in a new user and network namespace. Reject the all-zeros address in vxlan_mdb_is_valid_source(), which covers both call sites. A (, G) entry is expressed by omitting the source, so nothing legitimate is refused. Discovered by XBOW, triaged by Baul Lee baul.lee@xbow.com

References

https://security-tracker.debian.org/tracker/CVE-2026-98122

Affected packages

Debian:13 / linux

Package

Name: linux
Purl: pkg:deb/debian/linux?arch=source&distro=trixie

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

6.*

6.12.38-1

6.12.41-1

6.12.43-1~bpo12+1

6.12.43-1

6.12.48-1

6.12.57-1~bpo12+1

6.12.57-1

6.12.63-1~bpo12+1

6.12.63-1

6.12.69-1~bpo12+1

6.12.69-1

6.12.73-1~bpo12+1

6.12.73-1

6.12.74-1

6.12.74-2~bpo12+1

6.12.74-2

6.12.85-1~bpo12+1

6.12.85-1

6.12.86-1~bpo12+1

6.12.86-1

6.12.88-1~bpo12+1

6.12.88-1

6.12.90-1~bpo12+1

6.12.90-1

6.12.90-2~bpo12+1

6.12.90-2

6.12.94-1~bpo12+1

6.12.94-1

6.12.95-1~bpo12+1

6.12.95-1

6.12.96-1

6.12.100-1

6.12.101-1

6.12.105-1

6.12.107-1

6.13~rc6-1~exp1

6.13~rc7-1~exp1

6.13.2-1~exp1

6.13.3-1~exp1

6.13.4-1~exp1

6.13.5-1~exp1

6.13.6-1~exp1

6.13.7-1~exp1

6.13.8-1~exp1

6.13.9-1~exp1

6.13.10-1~exp1

6.13.11-1~exp1

6.14.3-1~exp1

6.14.5-1~exp1

6.14.6-1~exp1

6.15~rc7-1~exp1

6.15-1~exp1

6.15.1-1~exp1

6.15.2-1~exp1

6.15.3-1~exp1

6.15.4-1~exp1

6.15.5-1~exp1

6.15.6-1~exp1

6.16~rc7-1~exp1

6.16-1~exp1

6.16.1-1~exp1

6.16.3-1~bpo13+1

6.16.3-1

6.16.5-1

6.16.6-1

6.16.7-1

6.16.8-1

6.16.9-1

6.16.10-1

6.16.11-1

6.16.12-1~bpo13+1

6.16.12-1

6.16.12-2

6.17.2-1~exp1

6.17.5-1~exp1

6.17.6-1

6.17.7-1

6.17.7-2

6.17.8-1~bpo13+1

6.17.8-1

6.17.9-1

6.17.10-1

6.17.11-1

6.17.12-1

6.17.13-1~bpo13+1

6.17.13-1

6.18~rc4-1~exp1

6.18~rc4-1~exp2

6.18~rc5-1~exp1

6.18~rc6-1~exp1

6.18~rc7-1~exp1

6.18.1-1~exp1

6.18.2-1~exp1

6.18.3-1

6.18.5-1~bpo13+1

6.18.5-1

6.18.8-1

6.18.9-1~bpo13+1

6.18.9-1

6.18.10-1

6.18.12-1~bpo13+1

6.18.12-1

6.18.13-1

6.18.14-1

6.18.15-1~bpo13+1

6.18.15-1

6.19~rc4-1~exp1

6.19~rc5-1~exp1

6.19~rc6-1~exp1

6.19~rc7-1~exp1

6.19~rc8-1~exp1

6.19-1~exp1

6.19.2-1~exp1

6.19.3-1~exp1

6.19.4-1~exp1

6.19.5-1~exp1

6.19.6-1

6.19.6-2~bpo13+1

6.19.6-2

6.19.8-1~bpo13+1

6.19.8-1

6.19.10-1~bpo13+1

6.19.10-1

6.19.11-1~bpo13+1

6.19.11-1

6.19.12-1

6.19.13-1~bpo13+1

6.19.13-1

6.19.14-1~bpo13+1

6.19.14-1

7.*

7.0-1~exp1

7.0.1-1~exp1

7.0.3-1

7.0.4-1~bpo13+1

7.0.4-1

7.0.7-1~bpo13+1

7.0.7-1

7.0.9-1~bpo13+1

7.0.9-1

7.0.10-1~bpo13+1

7.0.10-1

7.0.12-1

7.0.12-2~bpo13+1

7.0.12-2

7.0.13-1~bpo13+1

7.0.13-1

7.0.14-1

7.1~rc2-1~exp1

7.1~rc3-1~exp1

7.1~rc4-1~exp1

7.1~rc4-1~exp2

7.1~rc5-1~exp1

7.1~rc7-1~exp1

7.1.1-1~exp1

7.1.2-1~exp1

7.1.3-1~bpo13+1

7.1.3-1

7.1.3-1+sunvdc

7.1.4-1

7.1.5-1

7.1.6-1

7.1.7-1~bpo13+1

7.1.7-1

7.1.8-1~bpo13+1

7.1.8-1

7.1.8-2

7.1.9-1

7.1.9-1+sparc64

7.1.10-1

7.1.12-1

7.1.13-1

7.2~rc3-1~exp1

7.2~rc5-1~exp1

7.2~rc7-1~exp1

7.2.2-1~exp1

7.2.3-1~exp1

7.2.6-1

7.2.7-1

Ecosystem specific

{
    "urgency":  "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-98122.json"

Debian:14 / linux