CVE-2026-15310VulnerabilityPublished 8 Sep 2026Updated 30 Oct 2026

Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update

Affects Red HatSource GCVE Database

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Authoritative record:CVE-2026-15310· Low 2.1

Not known to be exploited · CVSS 2.1 Low · fixed in Red Hat package updates : update Red Hat CPython when convenient.

Data as of 30 Oct 2026, 08:02 UTC

CVSS 4.0 base score

2.1Low

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 3.15.0rc2, 3.14.8, 3.13.16 +3

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: Present
Privileges Required: None
User Interaction: Active
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: Present: The successful attack depends on the presence of specific deployment and execution conditions of the vulnerable system that enable the attack. These include: a race condition must be won to successfully exploit the vulnerability (the successfulness of the attack is conditioned on execution conditions that are not under full control of the attacker, or the attack may need to be launched multiple times against a single target before being successful); the attacker must inject themselves into the logical network path between the target and the resource requested by the victim (e.g. vulnerabilities requiring an on-path attacker).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: Active: Successful exploitation of this vulnerability requires a targeted user to perform specific, conscious interactions with the vulnerable system and the attacker’s payload, or the user’s interactions would actively subvert protection mechanisms which would lead to exploitation of the vulnerability.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 25 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 29 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

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
Python Software FoundationCPython	Affected >=3.15.0a1 <3.15.0rc2	Fixed in 3.15.0rc2
Python Software FoundationCPython	Affected >=3.14.0 <3.14.8	Fixed in 3.14.8
Python Software FoundationCPython	Affected >=3.13.0 <3.13.16	Fixed in 3.13.16
Python Software FoundationCPython	Affected >=3.12.0 <3.12.15	Fixed in 3.12.15
Python Software FoundationCPython	Affected >=3.11.0 <3.11.17	Fixed in 3.11.17
Python Software FoundationCPython	Affected <3.10.22	Fixed in 3.10.22

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Apply the updated python3.10 RPM packages provided by Red Hat Hardened Images as listed in the advisory (version 3.10.21-1.1.hum1). Since the advisory includes updated packages, a fix is available and should be applied to affected systems. Systems that do not parse untrusted compressed files or that limit process memory via container or cgroup constraints have minimal operational risk. No additional mitigations are specified by Red Hat.

Description

A security update for Red Hat Hardened Images RPMs addresses multiple vulnerabilities in Python 3.10, including CVE-2026-15310. This particular flaw involves Python decompressing specially crafted zip files using bzip, LZMA, or Zstandard compression methods, which may cause excessive memory allocation leading to a denial of service (DoS). The vulnerabilities require an application or user to parse untrusted archives, limiting the impact to process-level resource exhaustion. Red Hat notes that typical environments do not automatically process untrusted archives, reducing operational risk. The update includes new RPM packages for python3.10 and related components.

Impact

Successful exploitation can cause excessive memory consumption leading to denial of service at the process level. There is no impact on confidentiality or integrity. The vulnerability requires that an application or user explicitly parse untrusted, malicious compressed archives. Systems that do not process such files or that enforce memory limits via containers or cgroups face minimal risk. No remote code execution or data disclosure is associated with this vulnerability.

Summary

This Red Hat security advisory updates python3.10 RPMs to address four CVEs, including CVE-2026-15310, which is a denial of service vulnerability caused by Python pre-allocating memory based on attacker-controlled sizes when decompressing malicious zip files using bzip, LZMA, or Zstandard compression. Exploitation requires parsing untrusted archives, limiting impact to process-level memory exhaustion rather than remote code execution or data disclosure. The advisory provides updated RPM packages for multiple python3.10 components on aarch64 and x86_64 architectures. Red Hat rates the severity as moderate (medium) and notes that typical usage scenarios do not automatically process untrusted archives, reducing risk. No known exploits in the wild are reported. The advisory does not specify fixed versions or patch availability explicitly but provides updated package versions to apply.

CWE-770Allocation of Resources Without Limits or Throttling (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #25
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Requirements
Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
Architecture and Design
Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V8.1.4 (opens in a new tab)
V13.4.1 (opens in a new tab)
V11.1.4 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Exponential Data Expansion (opens in a new tab)
Serialized Data Parameter Blowup (opens in a new tab)
Serialized Data with Nested Payloads (opens in a new tab)
Oversized Serialized Data Payloads (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-420Unprotected Alternate Channel (opens in a new tab)
Base weakness
The product protects a primary channel, but it does not use the same level of protection for an alternate channel.
Architecture and Design
Identify all alternate channels and use the same protection mechanisms that are used for the primary channels.
OWASP Cheat Sheets
Docker Security (opens in a new tab)
OWASP ASVS 4.0.3
V1.14.1 (opens in a new tab)
V1.4.4 (opens in a new tab)
V1.4.5 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-439Behavioral Change in New Version or Environment (opens in a new tab)
Base weakness
A's behavior or functionality changes with a new version of A, or a new environment, which is not known (or manageable) by B.
CWE-22Improper Limitation of a Pathname to a Restricted Directory (Path Traversal) (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #6OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.1 (opens in a new tab)
Attack patterns
Path Traversal (opens in a new tab)
Using Slashes and URL Encoding Combined to Bypass Validation Logic (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
Using Escaped Slashes in Alternate Encoding (opens in a new tab)
Using Slashes in Alternate Encoding (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

Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2026, 08:02 UTC

WeaknessesCWE-770, CWE-420, CWE-439 +1

Technical details

References

Community reviews

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