CVE-2026-54876VulnerabilityPublished 19 Aug 2026Updated 30 Oct 2026

Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

Affects Red HatSource GCVE Database

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Not known to be exploited.

Data as of 30 Oct 2026, 11:52 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 19 Aug 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

No broadly applicable mitigation is available. Operators can temporarily disable OCSP response checking in affected client applications if their certificate revocation policy permits, which blocks the vulnerable code path but disables OCSP-based revocation checks. Clients that must keep OCSP checking enabled remain exposed. Applying the updated openssl3 RPMs from Red Hat Hardened Images is recommended once available.

Description

A vulnerability in OpenSSL allows a malicious TLS server to cause a memory leak in client applications that enable OCSP response checking. This memory leak can lead to exhaustion of client memory and result in a denial of service (DoS) condition. Exploitation requires the client to process a specially crafted OCSP response from the server. No broadly applicable mitigation exists other than disabling OCSP response checking where policy permits, which removes OCSP-based revocation checks but blocks the vulnerable path.

Impact

A malicious TLS server can exploit this flaw to cause memory exhaustion in client applications that enable OCSP response checking, leading to denial of service. The impact is limited to clients that process OCSP responses and have this feature enabled. Confidentiality and integrity are not affected. The vulnerability can cause availability impact by crashing or degrading client applications over time.

Summary

CVE-2026-54876 is a vulnerability in OpenSSL where a malicious TLS server can send a specially crafted OCSP response during X.509 certificate chain verification, causing a memory leak in clients that have OCSP response checking enabled. Repeated connections to such a server can exhaust client memory, resulting in denial of service. The vulnerability is rated Important by Red Hat with a CVSS base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). The impact depends on client configuration, specifically whether OCSP response checking is enabled. No broad mitigation is available; disabling OCSP response checking can block the vulnerability but removes revocation checking. The update includes new RPMs for openssl3 packages, but no fixed versions are explicitly stated in the advisory.

CWE-772Missing Release of Resource after Effective Lifetime (opens in a new tab)
Base weaknessLikelihood of exploit: High
The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation
It is good practice to be responsible for freeing all resources you allocate and to be consistent with how and where you free resources in a function. If you allocate resources that you intend to free upon completion of the function, you must be sure to free the resources at all exit points for that function including…
Operation · Architecture and Design · Resource Limitation
Use resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available.
Attack patterns
HTTP DoS (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 30 Oct 2026, 09:59 UTC

WeaknessesCWE-772

Technical details

References

Community reviews

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