VulnerabilityPublished 11 Nov 2026

CVE-2026-119194: python-pyasn1 security update

Affects python-pyasn1Source GCVE Database

Compare

Mentioned vulnerabilities

Authoritative record:CVE-2026-119194· High 7.5

Not known to be exploited · CVSS 7.5 High : upgrade to 0.5.1-5.oe2403sp1 soon.

Data as of 11 Nov 2026, 14:49 UTC

CVSS 3.1 base score

7.5High

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	7.5

Patch: Available – fixed in 0.5.1-5.oe2403sp1

CVSS:3.1/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: None
Integrity: None
Availability: High

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, 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: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 29 Oct 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 11 Nov 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 python-pyasn1 to 0.5.1-5.oe2403sp1.

Affected software

Product	Affected	Fixed in
openEuler 24.03-LTS-SP1python-pyasn1`pkg:rpm/openEuler/python-pyasn1&distro=openEuler-24.03-LTS-SP1`Other threats	Affected <0.5.1-5.oe2403sp1	Fixed in 0.5.1-5.oe2403sp1

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

AI-suggested

A fixed version of python-pyasn1 is available in version 0.6.5. Users should upgrade to version 0.6.5 or later to remediate these CPU exhaustion vulnerabilities. No additional mitigation actions are required once the upgrade is applied.

Description

Multiple denial-of-service vulnerabilities exist in the python-pyasn1 library prior to version 0.6.5. These flaws involve quadratic CPU complexity during decoding of specially crafted ASN.1 BER, CER, or DER inputs with many fragments or colliding tag sets. An attacker can exploit these to exhaust CPU resources and reduce service availability without impacting confidentiality or integrity. The issues are fixed in version 0.6.5.

Impact

Exploitation of these vulnerabilities can cause CPU exhaustion on systems decoding attacker-controlled ASN.1 data using vulnerable pyasn1 versions. This results in denial of service by reducing service availability. There is no impact on confidentiality or integrity of data. No known exploits are reported in the wild.

Summary

The python-pyasn1 library versions before 0.6.5 contain several performance-related vulnerabilities that lead to CPU exhaustion during ASN.1 decoding. Specifically, schemaless container decoding stores every decoded component's TagSet in a growing set, causing quadratic CPU work when processing attacker-controlled inputs with many distinct long tag IDs whose TagSet hashes collide (CVE-2026-119194). Additionally, constructed string and indefinite-length ANY decoding repeatedly concatenate fragments, causing quadratic copying work (CVE-2026-119195). Constructed BIT STRING decoding involves repeated shifting and copying of an ever-growing bit value, also causing quadratic CPU usage (CVE-2026-119196). Finally, binary REAL decoding builds a large mantissa one octet at a time with repeated shifting and copying, resulting in quadratic decode time (CVE-2026-119197). These vulnerabilities allow an attacker to exhaust CPU resources during decoding, leading to denial of service. All these issues are addressed in pyasn1 version 0.6.5.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Nov 2026, 14:49 UTC

Technical details

References

Community reviews

Related threats