CVE-2026-98044bpf: Reject legacy packet loads from callbacks
- —Not scoredno CVSS score yet
- 0.17%Exploitation in 30 daysEPSS · top 94% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Reject legacy packet loads from callbacks check_ld_abs() models a failed BPF_LD_ABS or BPF_LD_IND in a subprogram as an implicit return with R0 set to zero. It calls prepare_func_exit() to explore this synthesized path. When the load is reached directly from a synchronous callback, prepare_func_exit() enforces the callback return contract and marks R0 precise. R0 is not derived from a real instruction on this path, so precision backtracking reaches the callback call with R0 still requested and triggers the "callback unexpected regs" verifier bug. A privileged program loader can therefore cause a verifier warning and an -EFAULT BPF_PROG_LOAD. These legacy packet-load instructions are deprecated. Reject them from callbacks rather than complicating their implicit-return model. Check all active frames before constructing the implicit return so nested static subprograms cannot hide the callback context. Global functions are verified independently with a fresh frame zero, so an active-frame check cannot identify a global function called from a callback. Also check the complete subprogram call graph during stack-depth validation and reject a function containing a legacy load when any caller is a callback. This covers global and static descendants without making has_ld_abs transitive, preserving its per-function BTF return-type check. Ordinary uses outside callbacks remain supported.
Timeline
ID reserved
By Linux
Published
- 26 days later
· 26 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.17% · top 94% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 8674e2db06cff6b50f2216eed9a761d15425bb34 – < cebda2a2bb4183550eae9dcf888c16407b4fffda
- affected ce01a4e5cfac7adbe0be565f90cd32ecbb2f8337 – < 3484a99303912db62428494a9061212049027e57
- affected ee861486e377edc55361c08dcbceab3f6b6577bd – < bc489c0c9b8c86bd7fac42cfd1bb152f042fca56
- affected ee861486e377edc55361c08dcbceab3f6b6577bd – < e7d28823c662128caae63f14e16bd394916c139b
- affected 928d354ae3557e8f755a227e67be88034eb3cd7f
- affected 8a800497d9f6c2ec9c2c1ba7b71d0ac2ea7f7bbe
- affected de1055e7f9e67af32b1f3376066272b04e5223c0
- affected 37ad2bb11e9de92cb7b94548705eeedd87f7d392
- affected d846d83bdacbd8f14fc45c63b8c1d22608452e1c
- affected 6.12.101 – < 6.12.114
- affected 6.18.42 – < 6.18.53
- affected 5.10.265 – < 5.11
- affected 5.15.216 – < 5.16
- affected 6.1.183 – < 6.2
- affected 6.6.148 – < 6.7
- affected 7.0.10 – < 7.1
- affected 7.1
- unaffected < 7.1
- unaffected 6.12.114 – ≤ 6.12.*
- unaffected 6.18.53 – ≤ 6.18.*
- unaffected 7.2.7 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References4
- https://git.kernel.org/stable/c/cebda2a2bb4183550eae9dcf888c16407b4fffda (opens in a new tab)
- https://git.kernel.org/stable/c/3484a99303912db62428494a9061212049027e57 (opens in a new tab)
- https://git.kernel.org/stable/c/bc489c0c9b8c86bd7fac42cfd1bb152f042fca56 (opens in a new tab)
- https://git.kernel.org/stable/c/e7d28823c662128caae63f14e16bd394916c139b (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-86697 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-98044)Record last updated .