CVE-2026-98629: net/sched: cls_u32: fix manual hash table handle IDR aliasing
Noroxi assessment
Priority: Monitor (action score 0/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.20% (FIRST EPSS).
- Fixed version: Linux Linux 0a5f5d9e94dead312d32c366b917c64e552b72f7, 0fac292d93fdb313099e98cce928b3a524c92c94, 21fc07924e996e1e661268ca269c86b8d59d25b3; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.159.1-1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 0a5f5d9e94dead312d32c366b917c64e552b72f7, 0fac292d93fdb313099e98cce928b3a524c92c94, 21fc07924e996e1e661268ca269c86b8d59d25b3; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.159.1-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_u32: fix manual hash table handle IDR aliasing A u32 hash table created with an explicit handle ('tc filter add ... handle 801: u32 divisor N') keys its IDR entry on the raw handle, while the destroy paths free it under handle2id(handle). The two key domains disagree for handles in the 0x800..0xFFF htid range: handle2id() folds them back into the auto-allocated id space (1..0x7FF). A manual table therefore leaves its raw-keyed IDR entry unreachable on delete (a permanent leak), and its delete can drop the idr entry of an unrelated live auto table. A later auto allocation can then hand out a handle that aliases the live manual table; u32_lookup_ht() first-match routes lookups and TCA_U32_LINK for that htid to the wrong table. Key the divisor-path alloc on handle2id(handle) so allocation and removal share one key domain. A manual handle that maps onto an id already in use is rejected with -ENOSPC, and auto allocation skips ids held by live manual tables. Conditions to recreate: ip link add test0 type dummy tc qdisc add dev test0 clsact tc filter add dev test0 ingress protocol ip pref 1 \ handle 801: u32 divisor 16 tc filter add dev test0 ingress protocol ip pref 2 u32 divisor 16 tc -d filter show dev test0 ingress | grep 'fh 801:' # unpatched: two live tables with handle 0x80100000 (the pref 2 root # hnode is auto-allocated id 1); patched: the auto hnode takes id 2. Also tested with a poc with a live u32 table on the block, add/delete a manual table 'handle 901: u32 divisor 1' twice; unpatched, the re-add fails with -ENOSPC because the raw key leaked on the first delete.
- Published
- Oct 18, 2026
- Updated
- Oct 19, 2026
- EPSS
- 0.2% · 10th percentile
- CWE
- —
Report tools
Action score
0
Monitor
Low priority for now.
- CVSS
- 0 / 40 · —
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 4403f9293ce9ecc2a55c688d84ee37e3ba0fc1a8, 6.12affected
- 9b2c3184e126b941dfa716b8128ed6db92a64e2f and later · before 21fc07924e996e1e661268ca269c86b8d59d25b3affected · git
- 789f9963bd031c3a185605665b744912df8e7eda and later · before 0fac292d93fdb313099e98cce928b3a524c92c94affected · git
- 73af53d82076bbe184d9ece9e14b0dc8599e6055 and later · before 54a454c5e41f5e2cb70c8163140ce095c5d5eefdaffected · git
- 73af53d82076bbe184d9ece9e14b0dc8599e6055 and later · before f6696481eedfd5752b4b56eed715d0b0fe48b9c5affected · git
- 73af53d82076bbe184d9ece9e14b0dc8599e6055 and later · before 2f898f9ec7c73c5697ee462681e7ea6984ee1f3daffected · git
- 73af53d82076bbe184d9ece9e14b0dc8599e6055 and later · before 0a5f5d9e94dead312d32c366b917c64e552b72f7affected · git
- 6.1.119 and later · before 6.1.189affected · semver
- 6.6.63 and later · before 6.6.158affected · semver
- 6.11.10 and later · before 6.12affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.190-1 | 6.1.190-1 |
| Debian:12 | linux-6.12 | before 6.12.113-1~deb12u1 | 6.12.113-1~deb12u1 |
| Debian:13 | linux | before 6.12.113-1 | 6.12.113-1 |
| Debian:14 | linux | before 7.2.9-1 | 7.2.9-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
Published before and after this one in the same product
- ← EarlierCVE-2026-98627Oct 18, 2026 · bpf: Preserve packet pointer class displacement in regsafe()0Monitor
- ← EarlierCVE-2026-98628Oct 18, 2026 · bpf: Make post-verification instruction rewrites killable0Monitor
- Later →CVE-2026-98630Oct 18, 2026 · eth: fbnic: Fix payload page pool error cleanup0Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 0a5f5d9e94dead312d32c366b917c64e552b72f7 | Vendor (CNA) |
| Linux Linux | 0fac292d93fdb313099e98cce928b3a524c92c94 | Vendor (CNA) |
| Linux Linux | 21fc07924e996e1e661268ca269c86b8d59d25b3 | Vendor (CNA) |
| Linux Linux | 2f898f9ec7c73c5697ee462681e7ea6984ee1f3d | Vendor (CNA) |
| Linux Linux | 54a454c5e41f5e2cb70c8163140ce095c5d5eefd | Vendor (CNA) |
| Linux Linux | 6.1.189 | Vendor (CNA) |
| Linux Linux | 6.12 | Vendor (CNA) |
| Linux Linux | 6.6.158 | Vendor (CNA) |
| Linux Linux | f6696481eedfd5752b4b56eed715d0b0fe48b9c5 | Vendor (CNA) |
| azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 | 6.6.159.1-1 · Release Notes | Microsoft (MSRC) |
| debian:linux | 6.1.190-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.113-1~deb12u1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- Fix recordedsame day
- TodayNov 7, 2026+20 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-1351 · Oct 19, 2026(Linux Kernel Güvenlik Bildirimi)
Technical details
No CVSS vector for this record, so attack conditions can't be derived.
Weakness class (CWE)
—
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Exploit maturity— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (5 more)Show less
- git.kernel.org/stable/c/0fac292d93fdb313099e98cce928b3a524c92c94
- git.kernel.org/stable/c/21fc07924e996e1e661268ca269c86b8d59d25b3
- git.kernel.org/stable/c/2f898f9ec7c73c5697ee462681e7ea6984ee1f3d
- git.kernel.org/stable/c/54a454c5e41f5e2cb70c8163140ce095c5d5eefd
- git.kernel.org/stable/c/f6696481eedfd5752b4b56eed715d0b0fe48b9c5
Vendor advisories and official records. Exploit/PoC links are deliberately left out.