In hpack_dht_insert in hpack-tbl.c in the HPACK decoder in HAProxy 1.8 through 2.x before 2.1.4, a remote attacker can write arbitrary bytes around a certain location on the heap via a crafted HTTP/2 request, possibly causing remote code execution.
CVE-2020-11100
Score elevated to 8.9 because EPSS predicts 61% probability of exploitation within the next 30 days (top 0.9% of all CVEs). NVD baseline CVSS 8.8 retained for reference. Confidence: see factors.
- High exploitation likelihood — EPSS 61%
A fix is available — apply it.
- CVSS v3
- 8.8
- EG Score
- 8.9(high)
- EG Risk
- 69(Track)EG Risk 69/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity89% × 45%Exploitation61% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 61%
- EPSS %ILE
- 99%
- KEV
- Not listed
Published
April 2, 2020
Last Modified
November 21, 2024
References (28)
- cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2020-04/msg00002.html
- cve@mitrehttp://packetstormsecurity.com/files/157323/haproxy-hpack-tbl.c-Out-Of-Bounds-Write.html
- cve@mitrehttp://www.haproxy.org
- cve@mitrehttps://bugzilla.redhat.com/show_bug.cgi?id=1819111
- cve@mitrehttps://bugzilla.suse.com/show_bug.cgi?id=1168023
- cve@mitrehttps://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=5dfc5d5cd0d2128d77253ead3acf03a421ab5b88
- cve@mitrehttps://lists.debian.org/debian-security-announce/2020/msg00052.html
- cve@mitrehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/264C7UL3X7L7QE74ZJ557IOUFS3J4QQC/
- cve@mitrehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MNW5RZLIX7LOXRLV7WMHX22CI43XSXKW/
- cve@mitrehttps://security.gentoo.org/glsa/202012-22
- cve@mitrehttps://usn.ubuntu.com/4321-1/
- cve@mitrehttps://www.debian.org/security/2020/dsa-4649
- cve@mitrehttps://www.haproxy.org/download/2.1/src/CHANGELOG
- cve@mitrehttps://www.mail-archive.com/haproxy%40formilux.org/msg36876.html
- af854a3a-2127-422b-91ae-364da2661108http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00002.html
Vendor Advisories for CVE-2020-11100(5)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2020:1936Red Hat Product SecurityMedium
Red Hat Security Advisory: OpenShift Container Platform 4.4.3 haproxy security update
- RHSA-2020:1287Red Hat Product SecurityCritical
Red Hat Security Advisory: OpenShift Container Platform 3.11 security update
- RHSA-2020:1288Red Hat Product SecurityCritical
Red Hat Security Advisory: haproxy security update
- RHSA-2020:1290Red Hat Product SecurityCritical
Red Hat Security Advisory: rh-haproxy18-haproxy security update
- RHSA-2020:1289Red Hat Product SecurityCritical
Red Hat Security Advisory: haproxy security update
Patch Availability(6)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | vim-haproxy (2.0.5-1ubuntu0.4) @ eoan | 2026-05-27 | ubuntu |
| redhat | haproxy-0:2.0.13-3.el7 | 2020-05-04 | redhat |
| redhat | haproxy-0:1.8.23-3.el7 | 2020-04-07 | redhat |
| redhat | haproxy-0:1.8.15-6.el8_1.1 | 2020-04-02 | redhat |
| redhat | haproxy-0:1.8.15-5.el8_0.1 | 2020-04-02 | redhat |
| redhat | rh-haproxy18-haproxy-0:1.8.17-1.el7.1 | 2020-04-02 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(1)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
Data Freshness Timeline
(refreshed 10× in last 7d / 34× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-26 14:51 UTCEPSS rescore
- 2026-07-25 14:14 UTCEPSS rescore
- 2026-07-24 14:14 UTCEPSS rescore
- 2026-07-23 14:15 UTCEPSS rescore
- 2026-07-23 14:15 UTCEPSS rescore
- 2026-07-23 01:48 UTCEG score recompute▲ 0.10
- 2026-07-22 22:32 UTCEG score recompute
- 2026-07-22 14:05 UTCEPSS rescore
- 2026-07-21 15:22 UTCEPSS rescore
- 2026-07-21 15:22 UTCEPSS rescore
- 2026-07-20 17:04 UTCEPSS rescore
- 2026-07-19 14:59 UTCOSV refresh
- 2026-07-19 14:28 UTCEPSS rescore
- 2026-07-19 14:28 UTCEPSS rescore
- 2026-07-18 10:02 UTCEPSS rescore
- 2026-07-16 16:59 UTCEPSS rescore
- 2026-07-16 16:59 UTCEPSS rescore
- 2026-07-15 16:55 UTCEPSS rescore
- 2026-07-13 22:27 UTCEPSS rescore
- 2026-07-13 06:10 UTCEPSS rescore
- 2026-07-13 06:10 UTCEPSS rescore
- 2026-07-12 05:44 UTCEPSS rescore
- 2026-07-11 08:24 UTCEPSS rescore
- 2026-07-09 19:06 UTCEPSS rescore
- 2026-07-06 16:25 UTCEPSS rescore
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- 2026-07-06 16:25 UTCEPSS rescore
- 2026-07-05 02:27 UTCEPSS rescore
- 2026-07-02 02:47 UTCOSV refresh
- 2026-07-01 15:03 UTCEPSS rescore
- 2026-07-01 15:03 UTCEPSS rescore
- 2026-06-30 23:20 UTCEPSS rescore
- 2026-06-30 23:20 UTCEPSS rescore
- 2026-06-28 04:54 UTCEPSS rescore
- 2026-06-28 04:54 UTCEPSS rescore
- 2026-06-27 03:06 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-23 21:31 UTCEPSS rescore
- 2026-06-23 21:31 UTCEPSS rescore
- 2026-06-22 14:23 UTCEPSS rescore
- 2026-06-22 14:23 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-18 17:50 UTCEPSS rescore
- 2026-06-18 17:50 UTCEPSS rescore
- 2026-06-17 17:50 UTCEPSS rescore
- 2026-06-17 17:50 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
- 2026-06-15 17:46 UTCEPSS rescore
- 2026-06-14 05:43 UTCOSV refresh
- 2026-06-13 22:58 UTCEPSS rescore
- 2026-06-13 22:58 UTCEPSS rescore
- 2026-06-12 23:09 UTCEPSS rescore
- 2026-06-11 13:58 UTCEPSS rescore
- 2026-06-10 22:16 UTCEPSS rescore
- 2026-06-10 22:16 UTCEPSS rescore
- 2026-06-10 13:20 UTCEPSS rescore
- 2026-06-08 14:15 UTCEPSS rescore
- 2026-06-08 14:15 UTCEPSS rescore
- 2026-06-07 15:23 UTCEPSS rescore
- 2026-06-07 15:23 UTCEPSS rescore
- 2026-06-05 22:45 UTCEPSS rescore
- 2026-06-05 22:45 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-01 13:50 UTCEPSS rescore
- 2026-05-31 22:29 UTCEPSS rescore
- 2026-05-31 22:29 UTCEPSS rescore
- 2026-05-31 00:15 UTCEPSS rescore
- 2026-05-31 00:14 UTCEPSS rescore
- 2026-05-29 13:42 UTCEPSS rescore
- 2026-05-29 13:42 UTCEPSS rescore
- 2026-05-28 13:43 UTCEPSS rescore
- 2026-05-28 13:43 UTCEPSS rescore
- 2026-05-27 13:39 UTCEPSS rescore
- 2026-05-27 05:39 UTCEG score recompute
- 2026-05-27 05:39 UTCVendor advisory
- 2026-05-27 05:39 UTCGHSA enrichment
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-24 16:21 UTCOSV refresh
Related CVEs(same vendor + same CWE)
Same vendor
10 shownredhat
- CVE-2001-0825EG 10.0HIGH
- CVE-2001-1009EG 10.0EPSS p93HIGH
- CVE-2001-0554EG 10.0EPSS p98HIGH
- CVE-2001-1162EG 10.0EPSS p96HIGH
- CVE-2001-0414EG 10.0EPSS p100HIGH
- CVE-2001-0191EG 10.0EPSS p92HIGH
- CVE-2001-0301EG 10.0EPSS p90HIGH
- CVE-2001-0197EG 10.0EPSS p96HIGH
- CVE-2001-0233EG 10.0EPSS p96HIGH
- CVE-2001-0010EG 10.0EPSS p98HIGH
Same CWE
10 shownCWE-787
Frequently asked(5)
What is CVE-2020-11100?
When was CVE-2020-11100 disclosed?
Is CVE-2020-11100 actively exploited?
What is the CVSS score of CVE-2020-11100?
How do I remediate CVE-2020-11100?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2020-11100
Is Your Infrastructure Affected by CVE-2020-11100?
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