How severe is CVE-2021-29648?

CVE-2021-29648 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-29648 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-29648?

CVE-2021-29648 primarily affects Linux Linux Kernel. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-29648?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-29648 published?

CVE-2021-29648 was published on 2021-03-30 and last updated on 2026-06-17.

CVE-2021-29648

CVE-2021-29648 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-307.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 4.9
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-307
Affected product: Linux Linux Kernel
Published: 2021-03-30
Last modified: 2026-06-17

Description

An issue was discovered in the Linux kernel before 5.11.11. The BPF subsystem does not properly consider that resolved_ids and resolved_sizes are intentionally uninitialized in the vmlinux BPF Type Format (BTF), which can cause a system crash upon an unexpected access attempt (in map_create in kernel/bpf/syscall.c or check_btf_info in kernel/bpf/verifier.c), aka CID-350a5c4dd245.

Frequently asked questions

What is CVE-2021-29648?: An issue was discovered in the Linux kernel before 5.11.11. The BPF subsystem does not properly consider that resolved_ids and resolved_sizes are intentionally uninitialized in the vmlinux BPF Type Format (BTF), which can cause a system crash upon an unexpected access attempt (in map_create in kernel/bpf/syscall.c or check_btf_info in kernel/bpf/verifier.c), aka CID-350a5c4dd245.
How severe is CVE-2021-29648?: CVE-2021-29648 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-29648 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-29648?: CVE-2021-29648 primarily affects Linux Linux Kernel. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-29648?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-29648 published?: CVE-2021-29648 was published on 2021-03-30 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

More vulnerabilities in Linux Linux Kernel

CVE-2023-2163 — Critical (CVSS 10.0): Incorrect verifier pruning in BPF in Linux Kernel >=5.4 leads to unsafe code paths being incorrectly marked as safe,…
CVE-2015-8104 — Critical (CVSS 10.0): The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a…
CVE-2015-1421 — Critical (CVSS 10.0): Use-after-free vulnerability in the sctp_assoc_update function in net/sctp/associola.c in the Linux kernel before…
CVE-2014-2523 — Critical (CVSS 10.0): net/netfilter/nf_conntrack_proto_dccp.c in the Linux kernel through 3.13.6 uses a DCCP header pointer incorrectly,…
CVE-2010-2495 — Critical (CVSS 10.0): The pppol2tp_xmit function in drivers/net/pppol2tp.c in the L2TP implementation in the Linux kernel before 2.6.34 does…
CVE-2010-2521 — Critical (CVSS 10.0): Multiple buffer overflows in fs/nfsd/nfs4xdr.c in the XDR implementation in the NFS server in the Linux kernel before…

All CVEs affecting Linux Linux Kernel →

Other CWE-307 (Improper Restriction of Excessive Authentication Attempts) vulnerabilities

CVE-2026-6853 — Critical (CVSS 9.8): Improper restriction of excessive authentication attempts vulnerability in Başbelen Group Food Cafe Businesses…
CVE-2026-8760 — Critical (CVSS 9.8): The Login with OTP plugin for WordPress is vulnerable to authentication bypass in all versions up to, and including,…
CVE-2020-37228 — Critical (CVSS 9.8): iDS6 DSSPro Digital Signage System 6.2 contains a CAPTCHA security bypass vulnerability that allows attackers to bypass…
CVE-2026-33879 — Critical (CVSS 9.8): Federated Learning and Interoperability Platform (FLIP) is an open-source platform for federated training and…
CVE-2026-33640 — Critical (CVSS 9.8): Outline is a service that allows for collaborative documentation. Outline implements an Email OTP login flow for users…
CVE-2026-31851 — Critical (CVSS 9.8): Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 does not implement rate limiting or account lockout…

Browse all CWE-307 (Improper Restriction of Excessive Authentication Attempts) vulnerabilities →