CVE-2026-53671PREVAIL: Context-write no-op in do_mem_store allows unsafe eBPF programs to pass verification
Updated under an hour ago ()
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It affects vbpf prevail. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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PREVAIL is a Polynomial-Runtime EBPF Verifier using an Abstract Interpretation Layer. Prior to version 0.2.4, the abstract transformer in prevail treats writes through a T_CTX-typed base register as a silent no-op: do_mem_store in src/crab/ebpf_transformer.cpp only models T_STACK stores, and the checker's T_CTX bounds arm never tests AccessType::write. An attacker can craft an eBPF program that overwrites a context field (e.g., ctx->data), reload that field typed as T_PACKET, and dereference an attacker-controlled address — and prevail will report the program as safe. This issue has been patched in version 0.2.4.
- CVSS
- 9.3 CRITICAL (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- Weakness (CWE)
- CWE-682
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Awaiting Analysis
- Record last updated
- Sep 5, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
vbpf prevail vbpf:prevail (from the name) | before 0.2.4 | CNA record |
References
- https://github.com/vbpf/prevail/security/advisories/GHSA-65rv-h458-cq99x-refsource-confirm
- https://github.com/vbpf/prevail/commit/de65234f67d2608b54d12571edb585ead224363cx-refsource-misc
- https://github.com/vbpf/prevail/releases/tag/v0.2.4x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.