CVE-2026-52934
CVE-2026-52934 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: High (CVSS 3.x base score 8.8)
- EPSS exploit prediction: 0% (16th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-38704
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
In the Linux kernel, the following vulnerability has been resolved: batman-adv: tvlv: reject oversized TVLV packets batadv_tvlv_container_ogm_append() builds a TVLV packet section from the tvlv.container_list. The total size of this section is computed by batadv_tvlv_container_list_size(), which sums the sizes of all registered containers. The return type and accumulator in batadv_tvlv_container_list_size() were u16. If the accumulated size exceeds U16_MAX, the value wraps around, causing the subsequent allocation in batadv_tvlv_container_ogm_append() to be undersized. The memcpy-style copy that follows would then write beyond the end of the allocated buffer, corrupting kernel memory. Fix this by widening the return type of batadv_tvlv_container_list_size() to size_t. In batadv_tvlv_container_ogm_append(), check the computed length against U16_MAX before proceeding, and bail out as if the allocation had failed when the limit is exceeded.
Frequently asked questions
- What is CVE-2026-52934?
- In the Linux kernel, the following vulnerability has been resolved: batman-adv: tvlv: reject oversized TVLV packets batadv_tvlv_container_ogm_append() builds a TVLV packet section from the tvlv.container_list. The total size of this section is computed by batadv_tvlv_container_list_size(), which sums the sizes of all registered containers. The return type and accumulator in batadv_tvlv_container_list_size() were u16. If the accumulated size exceeds U16_MAX, the value wraps around, causing the subsequent allocation in batadv_tvlv_container_ogm_append() to be undersized. The memcpy-style copy that follows would then write beyond the end of the allocated buffer, corrupting kernel memory. Fix this by widening the return type of batadv_tvlv_container_list_size() to size_t. In batadv_tvlv_container_ogm_append(), check the computed length against U16_MAX before proceeding, and bail out as if the allocation had failed when the limit is exceeded.
- How severe is CVE-2026-52934?
- CVE-2026-52934 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2026-52934 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-52934?
- CVE-2026-52934 primarily affects Linux Linux Kernel. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2026-52934?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-52934 have an EU (EUVD) identifier?
- Yes. CVE-2026-52934 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38704.
- When was CVE-2026-52934 published?
- CVE-2026-52934 was published on 2026-06-24 and last updated on 2026-07-08.
References
- https://git.kernel.org/stable/c/13493b00dd1e05a705981e052158652ea23eb482
- https://git.kernel.org/stable/c/1595628a2f877d052eda18865ccf539392c47c04
- https://git.kernel.org/stable/c/6448a49344e87487b61bd88cb850cd694a0f576d
- https://git.kernel.org/stable/c/94a3d72cd9b21116d7c6d5bdc57c11401fc28557
- https://git.kernel.org/stable/c/94db72e9dac202e017ee3db22c59d17e4f3bf171
- https://git.kernel.org/stable/c/c02aa6c0c9d1bea9bb75dea362b75ad225137bae
- https://git.kernel.org/stable/c/ede47988ac5687793745b17c1634a496a2299919
- https://git.kernel.org/stable/c/f50487e3566358b2b982b7801945e858c78ad9ab
Affected products (5)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*
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