CVSS 3.1
8.1 highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HCVE-2026-119618 Apache HTTP Server: mod_http2: heap corruption and RCE in assign_headers
High (8.1). EPSS 0.4% estimated probability of exploitation activity in the next 30 days.
On this page
Concurrent Execution using Shared Resource with Improper Synchronization vulnerability in Apache HTTP Server's mod_http2 in assign_headers() can lead to RCE.
This issue affects Apache HTTP Server: from 2.4.55 through 2.4.70.
Affected releases of mod_h2 from GitHub: from 2.0.8 through 2.0.42.
Severity
- EPSS
- 0.4% estimated probability of exploitation activity in the next 30 days; 36th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: no · Technical impact: total, assessed 2026-11-13. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition)
- OWASP Top 10
- A06:2025 Insecure Design
- Published
- Modified
- Assigned by
- apache (CNA)
- NVD analysis
- Analyzed
- Record from
- the NVD, synced
Ask an AI about this CVE
Show the prompt
Explain CVE-2026-119618 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-119618?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-119618?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-119618 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Badge for a README or a site
An image that stays current: it is drawn from the data each time it is fetched (a host that proxies images, as GitHub does, may show its copy for a while). Markdown:
[](https://cve.bz/cve/CVE-2026-119618)
HTML:
<a href="https://cve.bz/cve/CVE-2026-119618"><img src="https://cve.bz/cve/badge/CVE-2026-119618.svg" alt="CVE-2026-119618"></a>
Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| Apache Software Foundation Apache HTTP Server | from 2.4.55 through 2.4.70 |
Fix and patched versions
- Debian, Ubuntu, Red Hat, Rocky Linux, Alpine, Alpaquita: fixed package versions per release
- Patch: https://httpd.apache.org/security/vulnerabilities_24.html
- Patch: https://github.com/microsoft/azurelinux/pull/20165
- Vendor advisory: https://httpd.apache.org/security/vulnerabilities_24.html
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12 | apache2 | 2.4.71-1~deb12u1 | DEBIAN-CVE-2026-119618 |
| Debian | 13 | apache2 | 2.4.71-1~deb13u1 | DEBIAN-CVE-2026-119618 |
| Debian | 14 | apache2 | no fix listed | DEBIAN-CVE-2026-119618 |
| Ubuntu | 22.04:LTS | apache2 | 2.4.52-1ubuntu4.27 | UBUNTU-CVE-2026-119618 USN-9090-1 |
| Ubuntu | 24.04:LTS | apache2 | 2.4.58-1ubuntu8.19 | UBUNTU-CVE-2026-119618 USN-9090-1 |
| Ubuntu | 26.04:LTS | apache2 | 2.4.66-2ubuntu2.8 | UBUNTU-CVE-2026-119618 USN-9090-1 |
| Ubuntu | 26.10 | apache2 | 2.4.68-1ubuntu6.2 | UBUNTU-CVE-2026-119618 USN-9090-1 |
| Ubuntu | Pro:14.04:LTS | apache2 | 2.4.7-1ubuntu4.22+esm19 | USN-9090-1 |
| Ubuntu | Pro:16.04:LTS | apache2 | 2.4.18-2ubuntu3.17+esm24 | USN-9090-1 |
| Ubuntu | Pro:18.04:LTS | apache2 | 2.4.29-1ubuntu4.27+esm15 | USN-9090-1 |
| Ubuntu | Pro:20.04:LTS | apache2 | 2.4.41-4ubuntu3.23+esm11 | UBUNTU-CVE-2026-119618 USN-9090-1 |
| Red Hat | enterprise_linux:9::appstream | mod_http2, mod_http2-debuginfo, mod_http2-debugsource | 0:2.0.26-7.el9_9.1 | RHSA-2026:98981 |
| Red Hat | enterprise_linux:10.3 | mod_http2, mod_http2-debuginfo, mod_http2-debugsource | 0:2.0.29-5.el10_3.1 | RHSA-2026:98978 |
| Red Hat | enterprise_linux_eus:10.0 | mod_http2 | 0:2.0.29-2.el10_0.3 | RHSA-2026:98953 |
| Red Hat | enterprise_linux_eus:10.2 | mod_http2, mod_http2-debuginfo, mod_http2-debugsource | 0:2.0.29-4.el10_2.3 | RHSA-2026:98979 |
| Red Hat | hummingbird:1 | httpd, mod_lua, mod_ldap and 6 more | 0:2.4.71-0.1.hum1 | RHSA-2026:98998 |
| Red Hat | hummingbird:1 | mod_ssl, mod_proxy_html | 1:2.4.71-0.1.hum1 | RHSA-2026:98998 |
| Red Hat | rhel_e4s:9.4::appstream | mod_http2 | 0:2.0.26-2.el9_4.4 | RHSA-2026:98968 |
| Red Hat | rhel_eus:9.6::appstream | mod_http2 | 0:2.0.26-4.el9_6.3 | RHSA-2026:98954 |
| Red Hat | rhel_eus:9.8::appstream | mod_http2, mod_http2-debuginfo, mod_http2-debugsource | 0:2.0.26-6.el9_8.3 | RHSA-2026:98982 |
| Rocky Linux | 9 | mod_http2, mod_http2-debuginfo, mod_http2-debugsource | 0:2.0.26-7.el9_9.1 | RLSA-2026:98981 |
| Rocky Linux | 10 | mod_http2, mod_http2-debuginfo, mod_http2-debugsource | 0:2.0.29-5.el10_3.1 | RLSA-2026:98978 |
| Alpine | v3.21, v3.22, v3.23 and 1 more | apache2 | 2.4.71-r0 | ALPINE-CVE-2026-119618 |
| Alpaquita | stream | apache2 | 2.4.71-r0 | BELL-CVE-2026-119618 |
From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0; Red Hat Security Data © Red Hat, Inc., CC BY 4.0; Rocky Linux's errata, BSD-3-Clause; the Alpine secdb, CC BY-SA 4.0; BellSoft's OSV database, MIT. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu · Red Hat · Alpine · Alpaquita.
Red Hat
Red Hat rates this Critical.
The Red Hat Product Security team has assessed the severity of this vulnerability as Critical. It allows unauthenticated remote code execution, and public research has demonstrated a reliable exploit against a default-configured server with the mod_http2 module enabled. Successful exploitation allows an attacker to execute arbitrary commands, gain full control of the server process, and access or modify sensitive information.
The vulnerability's root cause is a thread-safety flaw in the mod_http2 module's handling of concurrent HTTP/2 requests: a worker thread writes into memory owned by the connection thread through a shared, lock-free allocator. This issue affects servers with HTTP/2 (h2 or h2c) enabled via the Protocols directive; servers serving only HTTP/1.1 are not affected.
Because exploitation depends on HTTP/2 stream workers sharing an allocator with the connection, the severity of this flaw varies across Red Hat products. The mod_http2 packages shipped in Red Hat Enterprise Linux 9 and Red Hat Enterprise Linux 10 allocate each HTTP/2 stream from a separate allocator, which substantially increases the complexity of exploiting the flaw. The severity for Red Hat Enterprise Linux 9 and Red Hat Enterprise Linux 10 is therefore rated Important rather than Critical. Versions of mod_http2 prior to 2.0.8 do not contain the affected code, and Red Hat Enterprise Linux 8 and earlier are not affected. Refer to the affected packages table for the severity assigned to each Red Hat product.
See the security bulletin for a detailed mitigation procedure.
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | mod_http2-0:2.0.29-5.el10_3.1 | Fixed 2026-11-11 | RHSA-2026:98978 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | mod_http2-0:2.0.29-2.el10_0.3 | Fixed 2026-11-11 | RHSA-2026:98953 |
| Red Hat Enterprise Linux 10.2 Extended Update Support | mod_http2-0:2.0.29-4.el10_2.3 | Fixed 2026-11-11 | RHSA-2026:98979 |
| Red Hat Enterprise Linux 9 | mod_http2-0:2.0.26-7.el9_9.1 | Fixed 2026-11-11 | RHSA-2026:98981 |
| Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | mod_http2-0:2.0.26-2.el9_4.4 | Fixed 2026-11-11 | RHSA-2026:98968 |
| Red Hat Enterprise Linux 9.6 Extended Update Support | mod_http2-0:2.0.26-4.el9_6.3 | Fixed 2026-11-11 | RHSA-2026:98954 |
| Red Hat Enterprise Linux 9.8 Extended Update Support | mod_http2-0:2.0.26-6.el9_8.3 | Fixed 2026-11-11 | RHSA-2026:98982 |
| Red Hat Enterprise Linux 6 | httpd | Not affected | |
| Red Hat Enterprise Linux 7 | httpd | Not affected | |
| Red Hat Enterprise Linux 8 | httpd:2.4/mod_http2 | Not affected | |
| Red Hat Hardened Images | httpd | Not affected | |
| Red Hat JBoss Core Services | jbcs-httpd24-mod_http2 | Affected |
Contains Red Hat Security Data © Red Hat, Inc., licensed under CC BY 4.0. Source: https://access.redhat.com/security/data. Modified: reformatted. Red Hat's page for CVE-2026-119618.
GitHub PoC (unverified)
Repositories on GitHub named after this CVE. Nobody has checked them and they are not scanned: some hold a working proof of concept, some nothing useful, and some malware made to look like one. Read the code before you run any of it.
- googlesky/CVE-2026-119618 8 stars, Python, created
Apache httpd mod_http2 (2.4.55-2.4.70) races on the connection allocator when assign_headers() writes the synthesised Content-Length: 0 int… - blkph0x/CVE-2026-119618-mod_http2-lab 0 stars, Python, created
Reproducible Apache mod_http2 CVE-2026-119618 source, HTTP/2, and debugger A/B lab - toeyhack/cve-2026-119618-apache-lab 0 stars, Shell, created
Script validation, Docker lab - LLCForge/CVE-2026-119618 0 stars, Python, created
Weaponised PoC driver for CVE-2026-119618, the mod_http2 assign_headers() race: header-table shaping, allocator free-list priming, controll… - geovanidps/cve-2026-119618-Apache 0 stars, Python, created
cve-2026-119618
3 more
- jeffschafer/Apache-HTTP2-RCE-HEAP-CORRUPTION-CVE-2026-119618-STAND-ALONE-SCANNER 0 stars, Shell, created
Independent community CLI scanners for Apache mod_http2 CVE-2026-119618 on Windows, Linux and macOS. - jeffschafer/Bigfix-Apache-HTTP2-Vulnerability-Scanner-CVE-2026-119618 0 stars, created
Passive BigFix Apache mod_http2 CVE-2026-119618 assessment pilot; archived review snapshot. - suominen/CVE-2026-119618 0 stars, Python, created
Attack patterns (CAPEC)
- CAPEC-26 Leveraging Race Conditions Likelihood: High · Severity: High
- CAPEC-29 Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions Likelihood: High · Severity: High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.
History
- Scored 8.1 high
- Analyzed by the NVD
Changes since this site first stored the record. The same for every record: /api/public/changes.
References
- https://httpd.apache.org/security/vulnerabilities_24.html
- https://github.com/microsoft/azurelinux/pull/20165
- http://www.openwall.com/lists/oss-security/2026/11/11/13
- https://access.redhat.com/security/cve/cve-2026-119618
- https://bugs.gentoo.org/986161
- https://github.com/AlmaLinux/updates/issues/4252
- https://ubuntu.com/security/CVE-2026-119618
- https://www.wiz.io/blog/cve-2026-119618-rce-apache-http-server-vulnerability