Answer in brief
CVE-2025-21958 records a Unknown severity vulnerability in Revert "openvswitch: switch to per-action label counting in conntrack". The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=fcb1aa5163b1ae4cf2864b688b08927aac51f51e <9e79fdabd52cfce1a021640a81256878a2c516a2 || >=fcb1aa5163b1ae4cf2864b688b08927aac51f51e <d91bfc64a4886102746e74d2c6f3a61e9a77fd7d || >=fcb1aa5163b1ae4cf2864b688b08927aac51f51e <1063ae07383c0ddc5bcce170260c143825846b03 | 9e79fdabd52cfce1a021640a81256878a2c516a2, d91bfc64a4886102746e74d2c6f3a61e9a77fd7d, 1063ae07383c0ddc5bcce170260c143825846b03 |
| Linux/Linuxgeneric | 6.12 | Not reported |
Published upstream
Apr 1, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: Revert "openvswitch: switch to per-action label counting in conntrack" Currently, ovs_ct_set_labels() is only called for confirmed conntrack entries (ct) within ovs_ct_commit(). However, if the conntrack entry does not have the labels_ext extension, attempting to allocate it in ovs_ct_get_conn_labels() for a confirmed entry triggers a warning in nf_ct_ext_add(): WARN_ON(nf_ct_is_confirmed(ct)); This happens when the conntrack entry is created externally before OVS increments net->ct.labels_used. The issue has become more likely since commit fcb1aa5163b1 ("openvswitch: switch to per-action label counting in conntrack"), which changed to use per-action label counting and increment net->ct.labels_used when a flow with ct action is added. Since there’s no straightforward way to fully resolve this issue at the moment, this reverts the commit to avoid breaking existing use cases.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2025-21958 records a Unknown severity vulnerability in Revert "openvswitch: switch to per-action label counting in conntrack". The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=fcb1aa5163b1ae4cf2864b688b08927aac51f51e <9e79fdabd52cfce1a021640a81256878a2c516a2 || >=fcb1aa5163b1ae4cf2864b688b08927aac51f51e <d91bfc64a4886102746e74d2c6f3a61e9a77fd7d || >=fcb1aa5163b1ae4cf2864b688b08927aac51f51e <1063ae07383c0ddc5bcce170260c143825846b03 | 9e79fdabd52cfce1a021640a81256878a2c516a2, d91bfc64a4886102746e74d2c6f3a61e9a77fd7d, 1063ae07383c0ddc5bcce170260c143825846b03 |
| Linux/Linuxgeneric | 6.12 | Not reported |
Published upstream
Apr 1, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: Revert "openvswitch: switch to per-action label counting in conntrack" Currently, ovs_ct_set_labels() is only called for confirmed conntrack entries (ct) within ovs_ct_commit(). However, if the conntrack entry does not have the labels_ext extension, attempting to allocate it in ovs_ct_get_conn_labels() for a confirmed entry triggers a warning in nf_ct_ext_add(): WARN_ON(nf_ct_is_confirmed(ct)); This happens when the conntrack entry is created externally before OVS increments net->ct.labels_used. The issue has become more likely since commit fcb1aa5163b1 ("openvswitch: switch to per-action label counting in conntrack"), which changed to use per-action label counting and increment net->ct.labels_used when a flow with ct action is added. Since there’s no straightforward way to fully resolve this issue at the moment, this reverts the commit to avoid breaking existing use cases.
Quoted source text, attributed separately from HOL analysis.