How severe is CVE-2021-36154?

CVE-2021-36154 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-36154 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-36154?

CVE-2021-36154 primarily affects Linuxfoundation Grpc Swift. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-36154?

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.

When was CVE-2021-36154 published?

CVE-2021-36154 was published on 2021-07-09 and last updated on 2026-06-17.

CVE-2021-36154

CVE-2021-36154 is a high-severity vulnerability in Linuxfoundation Grpc Swift with a CVSS 3.x base score of 7.5. 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-674.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-674
Affected product: Linuxfoundation Grpc Swift
Published: 2021-07-09
Last modified: 2026-06-17

Description

HTTP2ToRawGRPCServerCodec in gRPC Swift 1.1.1 and earlier allows remote attackers to deny service via the delivery of many small messages within a single HTTP/2 frame, leading to Uncontrolled Recursion and stack consumption.

Frequently asked questions

What is CVE-2021-36154?: HTTP2ToRawGRPCServerCodec in gRPC Swift 1.1.1 and earlier allows remote attackers to deny service via the delivery of many small messages within a single HTTP/2 frame, leading to Uncontrolled Recursion and stack consumption.
How severe is CVE-2021-36154?: CVE-2021-36154 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-36154 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-36154?: CVE-2021-36154 primarily affects Linuxfoundation Grpc Swift. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-36154?: 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.
When was CVE-2021-36154 published?: CVE-2021-36154 was published on 2021-07-09 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:linuxfoundation:grpc_swift:1.0.0:*:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:grpc_swift:1.1.0:*:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:grpc_swift:1.1.1:*:*:*:*:*:*:*

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