7.8

CVE-2019-9511: Some HTTP/2 implementations are vulnerable to window size manipulation and stream prioritization manipulation, potentially leading to a denial of service

Modified
AliasesALPINE-CVE-2019-9511UBUNTU-CVE-2019-9511DEBIAN-CVE-2019-9511
Published 13-08-2019Last modified 04-08-2024

Vulnerability summary

CVE-2019-9511 is a high (CVSS 7.8) Uncontrolled Resource Consumption vulnerability in apache traffic_server. EPSS estimates a 59.55% chance of exploitation in the next 30 days, higher than 99.1% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 60% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v2.0 (NVD)
EPSS score
59.55%
0%100%
Critical · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 42 · Related 19
DSA-4505-1DSA-4511-1DSA-4669-1MGASA-2019-0291MGASA-2019-0342MGASA-2020-0372

Timeline

  1. 13-08-2019
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability information updated.

Description

Some HTTP/2 implementations are vulnerable to window size manipulation and stream prioritization manipulation, potentially leading to a denial of service. The attacker requests a large amount of data from a specified resource over multiple streams. They manipulate window size and stream priority to force the server to queue the data in 1-byte chunks. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.

CVSS metrics

8 scores · 5 sources · 3 versions

EPSS trend

Probability

59.55%

Chance of exploitation in the next 30 days

Percentile

99%

Versus all other CVEs

30-day change

No change 0.00 pp

From 59.55% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Redhat6 products
Debian4 products
  • nghttp2< 1.39.2-1
  • nginx< 1.14.2-3
  • nodejs< 10.16.3~dfsg-1
  • debian_linuxEOL9.0 | 10.0
Alpine3 products
  • nghttp2< 1.39.2-r0 | < 1.35.1-r1
  • nginx≥ 1.9.5, < 1.16.1-r0 | ≥ 1.9.5, < 1.14.1-r1 | ≥ 1.9.5, < 1.14.1-r2
  • nodejs< 10.16.3-r0
Synology3 products
Ubuntu3 products
  • nghttp2< 1.7.1-1ubuntu0.1~esm2 | < 1.30.0-1ubuntu1+esm2
  • nginx< 1.10.3-0ubuntu0.16.04.4 | < 1.14.0-0ubuntu1.4
  • nodejsAll versions (No fix recorded)
Oracle2 products
Apache1 product
  • traffic_server≥ 6.0.0, ≤ 6.2.3 | ≥ 7.0.0, ≤ 7.1.6 | ≥ 8.0.0, ≤ 8.0.3
Apple1 product
Canonical1 product
F51 product
  • nginx≥ 1.9.5, < 1.16.1 | ≥ 1.17.0, ≤ 1.17.2
Fedoraproject1 product
Mcafee1 product
  • web_gateway≥ 7.7.2.0, < 7.7.2.24 | ≥ 7.8.2.0, < 7.8.2.13 | ≥ 8.1.0, < 8.2.0
Nodejs1 product
  • node.js≥ 8.0.0, ≤ 8.8.1 | ≥ 8.9.0, < 8.16.1 | ≥ 10.0.0, ≤ 10.12.0 | ≥ 10.13.0, < 10.16.3 | ≥ 12.0.0, < 12.8.1
Opensuse1 product

14 vendors · 29 products

References

57 links
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