CVE-2021-39204

mediumpriority · track · 21EPSS 0.017 · 77 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.66% (77th) EPSS

CVSS 5 · medium

Is it mine?

14 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-27

Pomerium is an open source identity-aware access proxy. Envoy, which Pomerium is based on, incorrectly handles resetting of HTTP/2 streams with excessive complexity. This can lead to high CPU utilization when a large number of streams are reset. This can result in a DoS condition. Pomerium versions 0.14.8 and 0.15.1 contain an upgraded envoy binary with this vulnerability patched.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · security-advisories@github.comexploitability 3.9 · impact 3.6

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · OSV

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-834USprimaryCWE-834US

affected products (14)

Products and version ranges known to be affected.

pomerium pomerium≤ < 0.14.8enisa_euvdEU
pomerium pomerium0.15.0, → 0.15.1enisa_euvdEU
envoyproxy envoy≤ 1.16.4nvdUScpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
envoyproxy envoy1.17.0 → 1.17.4nvdUScpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
envoyproxy envoy1.18.0 → 1.18.4nvdUScpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
envoyproxy envoy= 1.19.0nvdUScpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
pomerium pomerium< 0.14.8nvdUScpe:2.3:a:pomerium:pomerium:*:*:*:*:*:*:*:*
pomerium pomerium= 0.15.0nvdUScpe:2.3:a:pomerium:pomerium:*:*:*:*:*:*:*:*
Bitnami envoy< 1.16.5osvUSpkg:bitnami/envoy
Bitnami envoy1.17.0 → 1.17.4osvUSpkg:bitnami/envoy
Bitnami envoy1.18.0 → 1.18.4osvUSpkg:bitnami/envoy
Bitnami envoy1.19.0 → 1.19.1osvUSpkg:bitnami/envoy
Go github.com/pomerium/pomerium< 0.14.8osvUSpkg:golang/github.com/pomerium/pomerium
Go github.com/pomerium/pomerium0.15.0 → 0.15.1osvUSpkg:golang/github.com/pomerium/pomerium

advisories (2)

Vendor and ecosystem advisories describing this.

GHSA-5wjf-62hw-q78rExcessive CPU usage2021-09-10ghsa · osvUS
Envoy, which Pomerium is based on, incorrectly handles resetting of HTTP/2 streams with excessive complexity. This can lead to high CPU utilization when a large number of streams are reset. ### Impact This can result in a DoS condition. ### Patches Pomerium versions 0.14.8 and 0.15.1 contain an upgraded envoy binary with this vulnerability patched. ### Workarounds N/A ### References [envoy GSA](https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc) [envoy CVE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-32778) [envoy announcement](https://groups.google.com/g/envoy-announce/c/5xBpsEZZDfE/m/wD05NZBbAgAJ) ### For more information If you have any questions or comments about this advisory: * Open an issue in [pomerium/pomerium](https://github.com/pomerium/pomerium/issues) * Email us at [security@pomerium.com](mailto:security@pomerium.com)
BIT-envoy-2021-39204Excessive CPU usage in Pomerium2024-03-06vendor · osvUS
Pomerium is an open source identity-aware access proxy. Envoy, which Pomerium is based on, incorrectly handles resetting of HTTP/2 streams with excessive complexity. This can lead to high CPU utilization when a large number of streams are reset. This can result in a DoS condition. Pomerium versions 0.14.8 and 0.15.1 contain an upgraded envoy binary with this vulnerability patched.

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv nvd NVD CVE.org MITRE

published 2021-09-09modified 2026-06-17

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+135 more

references (10)

External citations — patches, advisories, analysis.

scry

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