HIGH
httpd: Read after free in mod_http2
Published Jul 13, 2017
7.5
HIGHCVSS 3.0
EPSS 9.58%
Description
When under stress, closing many connections, the HTTP/2 handling code in Apache httpd 2.4.26 would sometimes access memory after it has been freed, resulting in potentially erratic behaviour.
Affected products
-
- Version 2.4.26StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Apache Software Foundation | Apache HTTP Server | n/a |
|
- 2.4.26
No data.
Red Hat Enterprise Linux 5
httpd
Not affected
Red Hat Enterprise Linux 6
httpd
Not affected
Red Hat Enterprise Linux 7
httpd
Not affected
Red Hat JBoss Core Services
httpd
Not affected
Red Hat JBoss Enterprise Application Platform 5
httpd
Not affected
Red Hat JBoss Enterprise Application Platform 6
httpd
Not affected
Red Hat JBoss Enterprise Web Server 1
httpd
Not affected
Red Hat JBoss Enterprise Web Server 2
httpd
Not affected
Red Hat JBoss Web Server 3
httpd
Not affected
Red Hat Software Collections
httpd24-httpd
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | httpd | Not affected | n/a |
| Red Hat Enterprise Linux 6 | httpd | Not affected | n/a |
| Red Hat Enterprise Linux 7 | httpd | Not affected | n/a |
| Red Hat JBoss Core Services | httpd | Not affected | n/a |
| Red Hat JBoss Enterprise Application Platform 5 | httpd | Not affected | n/a |
| Red Hat JBoss Enterprise Application Platform 6 | httpd | Not affected | n/a |
| Red Hat JBoss Enterprise Web Server 1 | httpd | Not affected | n/a |
| Red Hat JBoss Enterprise Web Server 2 | httpd | Not affected | n/a |
| Red Hat JBoss Web Server 3 | httpd | Not affected | n/a |
| Red Hat Software Collections | httpd24-httpd | Not affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
7.5 HIGH NVD
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Impact None
Integrity Impact None
Availability Impact High
1 other source (Red Hat) ▾
6.5 MEDIUM Red Hat
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Impact Low
Integrity Impact None
Availability Impact High
5.0 MEDIUM NVD
AV:N/AC:L/Au:N/C:N/I:N/A:P
Access Vector Network
Access Complexity Low
Authentication None
Confidentiality Impact None
Integrity Impact None
Availability Impact Partial
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
9.58% 0.09584
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
EPSS probability 0.09584
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (28 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 9.58% (0.09584) | 95.33th | v5 (v2026.06.15) |
| Jun 15, 2026 | 9.51% (0.09507) | 94.80th | v5 (v2026.06.15) |
| May 31, 2026 | 10.12% (0.10122) | 93.23th | v4 (v2025.03.14) |
| May 10, 2026 | 6.09% (0.06093) | 90.84th | v4 (v2025.03.14) |
| Mar 28, 2026 | 12.19% (0.12192) | 93.79th | v4 (v2025.03.14) |
| Mar 8, 2026 | 10.58% (0.10582) | 93.16th | v4 (v2025.03.14) |
| Feb 5, 2026 | 12.54% (0.12542) | 93.76th | v4 (v2025.03.14) |
| Nov 21, 2025 | 11.51% (0.11506) | 93.33th | v4 (v2025.03.14) |
| Nov 18, 2025 | 29.64% (0.29642) | 96.35th | v4 (v2025.03.14) |
| Jul 27, 2025 | 12.23% (0.12230) | 93.54th | v4 (v2025.03.14) |
| Mar 30, 2025 | 18.61% (0.18609) | 94.75th | v4 (v2025.03.14) |
| Mar 29, 2025 | 16.37% (0.16374) | 91.48th | v4 (v2025.03.14) |
| Mar 17, 2025 | 18.61% (0.18609) | 94.77th | v4 (v2025.03.14) |
| Dec 17, 2024 | 2.11% (0.02110) | 88.85th | v3 (v2023.03.01) |
| Jan 7, 2024 | 3.76% (0.03759) | 90.92th | v3 (v2023.03.01) |
| Nov 8, 2023 | 5.23% (0.05228) | 92.17th | v3 (v2023.03.01) |
| Oct 17, 2023 | 4.00% (0.03998) | 91.02th | v3 (v2023.03.01) |
| Apr 28, 2023 | 3.94% (0.03945) | 90.66th | v3 (v2023.03.01) |
| Mar 7, 2023 | 5.48% (0.05482) | 91.98th | v3 (v2023.03.01) |
| Mar 6, 2023 | 5.24% (0.05242) | 89.75th | v2 (v2022.01.01) |
| Apr 1, 2022 | 5.24% (0.05242) | 88.72th | v2 (v2022.01.01) |
| Feb 4, 2022 | 5.24% (0.05242) | 75.28th | v2 (v2022.01.01) |
| Feb 3, 2022 | 12.82% (0.12821) | 88.92th | v1 |
| Jan 6, 2022 | 12.82% (0.12821) | 88.79th | v1 |
| Sep 1, 2021 | 12.82% (0.12821) | 95.95th | v1 |
| Jun 8, 2021 | 12.82% (0.12821) | 0.00th | v1 |
| Jun 3, 2021 | 11.83% (0.11832) | 0.00th | v1 |
| Apr 14, 2021 | 11.33% (0.11329) | 0.00th | v1 |
Weaknesses (1)
References (27)
- http://www.securityfocus.com/bid/99568 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1038907 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2017-9789 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1470750 Issue Tracking
- https://httpd.apache.org/security/vulnerabilities_24.html x_refsource_CONFIRMRelease NotesVendor Advisory
- https://httpd.apache.org/security/vulnerabilities_24.html#2.4.27
- https://lists.apache.org/thread.html/56c2e7cc9deb1c12a843d0dc251ea7fd3e7e80293cde02fcd65286ba%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/84a3714f0878781f6ed84473d1a503d2cc382277e100450209231830%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/9d0098775bd83cf7c33ac5a077ef412c14ce939198921e639c734e20%40%3Cannounce.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/r15f9aa4427581a1aecb4063f1b4b983511ae1c9935e2a0a6876dad3c%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/r476d175be0aaf4a17680ef98c5153b4d336eaef76fb2224cc94c463a%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/r6521a7f62276340eabdb3339b2aa9a38c5f59d978497a1f794af53be%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/r76142b8c5119df2178be7c2dba88fde552eedeec37ea993dfce68d1d%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/r9f93cf6dde308d42a9c807784e8102600d0397f5f834890708bf6920%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/rc998b18880df98bafaade071346690c2bc1444adaa1a1ea464b93f0a%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/rcc44594d4d6579b90deccd4536b5d31f099ef563df39b094be286b9e%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/rd18c3c43602e66f9cdcf09f1de233804975b9572b0456cc582390b6f%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/rd336919f655b7ff309385e34a143e41c503e133da80414485b3abcc9%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/re3d27b6250aa8548b8845d314bb8a350b3df326cacbbfdfe4d455234%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/rfcf929bd33a6833e3f0c35eebdad70d5060665f9c4e17ea467c66770%40%3Ccvs.httpd.apache.org%3E mailing-listx_refsource_MLIST
- https://nvd.nist.gov/vuln/detail/CVE-2017-9789
- https://security.gentoo.org/glsa/201710-32 vendor-advisoryx_refsource_GENTOO
- https://security.netapp.com/advisory/ntap-20170911-0002/ x_refsource_CONFIRM
- https://support.apple.com/HT208221 x_refsource_CONFIRM
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03908en_us x_refsource_CONFIRM
- https://www.cve.org/CVERecord?id=CVE-2017-9789
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner apache
Published Jul 13, 2017
Updated Sep 16, 2024
Reserved Jun 21, 2017
Link CVE-2017-9789
CISA Vulnrichment
Updated n/a