CVE-2026-72247

CVE CVE-2026-72247EUVD EUVD-2026-59146Veröffentlicht 2026-08-15T05:54:35.000ZZuletzt geändert 2026-08-17T05:41:58.000ZCVSS 7.5

Was das Advisory beschreibt

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conncount: fix zone comparison in tuple dedup The "already exists" dedup logic in __nf_conncount_add() decides whether a connection has already been counted and can be skipped instead of incrementing the connlimit count. It compares the conntrack zone of a list entry with the zone of the connection being added using nf_ct_zone_id() and nf_ct_zone_equal(), passing conn->zone.dir or zone->dir as the direction argument. Those helpers take enum ip_conntrack_dir values: IP_CT_DIR_ORIGINAL is 0 and IP_CT_DIR_REPLY is 1. However, zone->dir is a u8 bitmask: NF_CT_ZONE_DIR_ORIG is 1, NF_CT_ZONE_DIR_REPL is 2 and NF_CT_DEFAULT_ZONE_DIR is 3. Passing that bitmask as the enum direction shifts the meaning of every non-zero value. An ORIG-only zone passes 1 and is tested as REPLY, while REPL-only and default zones pass 2 or 3 and test bits beyond the valid direction range. In those cases nf_ct_zone_id() can fall back to NF_CT_DEFAULT_ZONE_ID instead of using the real zone id, so different zones can be treated as equal and dedup collapses to tuple equality alone. nf_conncount stores and compares the original-direction tuple for a connection. If an skb already has an attached conntrack entry, get_ct_or_tuple_from_skb() explicitly copies ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, regardless of the packet's ctinfo. Therefore the zone comparison in the tuple dedup path must use IP_CT_DIR_ORIGINAL as well; the zone direction bitmask describes where a zone id applies, not which direction this conncount tuple represents. Fix the two dedup comparisons by passing IP_CT_DIR_ORIGINAL directly. Do not special-case NF_CT_DEFAULT_ZONE_DIR and do not compare raw zone ids: using the existing helpers with IP_CT_DIR_ORIGINAL preserves the direction-aware NF_CT_DEFAULT_ZONE_ID fallback. A default bidirectional zone contains the ORIG bit, so it naturally returns the real zone id; reply-only zones continue to fall back for original-direction tuple comparisons.

Quelle: EUVD (ENISA), im Wortlaut der Meldung.

Produkte, die das Advisory nennt

Diese Angaben stammen aus der Meldung selbst, nicht aus einer Prüfung durch uns.

• Linux — Linux 4.14.92 <4.15; 525e1dffed8711973f77412729621098a95238e5; 21ba8847f857028dc83a0f341e16ecc616e34740 <6ff07ac5405bea4d4ead3559fc123f987576424a; patch: 6.6.145; 75af3d78168e654a5cd8bbc4c774f97be836165f; 21ba8847f857028dc83a0f341e16ecc616e34740 <7bdc3c0985ecf17b957811fedcc684acdf698acc; patch: 5.15.212; 4.18; patch: 0; 21ba8847f857028dc83a0f341e16ecc616e34740 <4f30a89c0ed2418719a1144881c2635b940b543d; 21ba8847f857028dc83a0f341e16ecc616e34740 <3cd9a5792cbea81139c24320986dd0db69e9b5d0; patch: 5.10.261; 21ba8847f857028dc83a0f341e16ecc616e34740 <82fc35e0da9a91db9a034f8311f18f77a599ae3f; 21ba8847f857028dc83a0f341e16ecc616e34740 <35a56e2a46b90e6bd4ca816b80e9cb8d20dfc3ce; patch: 7.2; patch: 6.1.178; patch: 6.12.97; patch: 6.18.40; 21ba8847f857028dc83a0f341e16ecc616e34740 <78b5d6dbc860776161f9e9206b06ff8a01f531ab; patch: 7.1.5; 21ba8847f857028dc83a0f341e16ecc616e34740 <f62c41b4910e65da396ec9a8c40c1fe7fe82e449

Die genannten Versionen sind die Angabe der Meldung. Patchlage vergleicht keine Versionsnummern und leitet aus ihnen keine Aussage ab — welche Version installiert ist, muss ein Mensch nachsehen.

Im Produktkatalog geführt

Für diese Produkte kann ein Bestand in Patchlage erfasst werden. Ein Advisory dazu erscheint am Morgen danach im Lagebericht.

• Linux — Linux

Patchlage meldet Treffer und Verdachtsfälle. Zu allem anderen sagt dieses System nichts — weder diese Seite noch der Lagebericht behauptet je, dass ein Bestand sicher ist.