CVE-2026-27651: F5 NGINX Open Source · NULL Pointer Dereference
Affects F5 NGINX Open SourceSource CVE Database V5
Not known to be exploited · CVSS 7.5 High : upgrade to 1.29.7 or 1.28.3 soon.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.9% chance of exploitation in 30 days – higher than 61% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.29.7, 1.28.3, R36 P3 +3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade NGINX Open Source to 1.29.7 or 1.28.3; NGINX Plus to R36 P3, R35 P2 or R32 P5; the Red Hat redhat/nginx package to 1.29.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| F5NGINX Open Source | Affected
| Fixed in
|
| F5NGINX Open Source | Affected
| Fixed in
|
| F5NGINX Plus | Affected
| Fixed in
|
Red Hatredhat/nginxpkg:rpm/redhat/nginxOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released security updates for affected packages in Red Hat Enterprise Linux 10.0 Extended Update Support and other supported variants. Applying these official vendor updates will remediate the vulnerability. Users should refer to the Red Hat advisories (e.g., RHSA-2026:13634) for detailed update instructions. Since this is not a cloud service, remediation depends on applying these patches. Patch status is confirmed by vendor advisories. No alternative mitigations are specified.
Description
When the ngx_mail_auth_http_module module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cause worker processes to terminate. This issue may occur when (1) CRAM-MD5 or APOP authentication is enabled, and (2) the authentication server permits retry by returning the Auth-Wait response header. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
References
- my.f5.com/manage/s/article/K000160383 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-27651 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2450791 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27651.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:13634 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:6906 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:6907 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:15942 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:14836 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:13839 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:15943 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:15945 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:13680 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:15966 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:6923 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:7002 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:7343 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:8346 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:10065 (opens in a new tab)