NVD / CVE Program· CNA GitHub_M

CVE-2026-59885: pyasn1: Quadratic complexity in OBJECT IDENTIFIER and RELATIVE-OID processing allows denial of service

HighCVSS 7.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 30/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.61% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: pyasn1 pyasn1 0.6.4; azl3 python-pyasn1 0.4.8-2 on Azure Linux 3.0 0.4.8-3.

Low priority for now. Upgrade to pyasn1 pyasn1 0.6.4; azl3 python-pyasn1 0.4.8-2 on Azure Linux 3.0 0.4.8-3 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER, CER, and DER decoders process OBJECT IDENTIFIER and RELATIVE-OID values in quadratic time relative to the number of arcs, so a small crafted payload containing an OID with many arcs consumes excessive CPU per decode() call and can deny service to applications that decode untrusted ASN.1 data. The corresponding encoders have the same quadratic behavior when an application re-encodes previously decoded attacker-supplied values. This issue is fixed in version 0.6.4.

Published: Jul 14, 2026
Updated: Jul 21, 2026
EPSS: 0.6% · 49th percentile
CWE: CWE-400

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.6%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 7.5; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
pyasn1	pyasn1	cpe:2.3:a:pyasn1:pyasn1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

pyasn1 pyasn1
- < 0.6.4affected

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

pyasn1 pyasn1before 0.6.4

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	pyasn1	before 0.4.8-3+deb12u3	0.4.8-3+deb12u3
Debian:13	pyasn1	before 0.6.1-1+deb13u3	0.6.1-1+deb13u3
Debian:14	pyasn1	before 0.6.4-1	0.6.4-1
openSUSE:Leap 16.0	python-pyasn1	before 0.6.1-160000.5.1	0.6.1-160000.5.1
openSUSE:Tumbleweed	python-pyasn1	before 0.6.4-1.1	0.6.4-1.1
PyPI	pyasn1	before 0.6.4	0.6.4
Red Hat:ansible_automation_platform_developer:2.5::el8	receptor	before 0:1.6.7-1.el8ap	0:1.6.7-1.el8ap
Red Hat:ansible_automation_platform_developer:2.5::el8	receptorctl	before 0:1.6.7-1.el8ap	0:1.6.7-1.el8ap
Red Hat:ansible_automation_platform_developer:2.5::el9	receptor	before 0:1.6.7-1.el9ap	0:1.6.7-1.el9ap
Red Hat:ansible_automation_platform_developer:2.5::el9	receptorctl	before 0:1.6.7-1.el9ap	0:1.6.7-1.el9ap
Red Hat:ansible_automation_platform_developer:2.6::el9	automation-controller	before 0:4.7.15-2.el9ap	0:4.7.15-2.el9ap
Red Hat:ansible_automation_platform_developer:2.6::el9	automation-controller-cli	before 0:4.7.15-2.el9ap	0:4.7.15-2.el9ap
Red Hat:ansible_automation_platform:2.5::el8	automation-controller-venv-tower	before 0:4.6.31-1.el8ap	0:4.6.31-1.el8ap
Red Hat:ansible_automation_platform:2.5::el8	automation-eda-controller	before 0:1.1.21-1.el8ap	0:1.1.21-1.el8ap
Red Hat:ansible_automation_platform:2.5::el8	automation-eda-controller-base	before 0:1.1.21-1.el8ap	0:1.1.21-1.el8ap
Red Hat:ansible_automation_platform:2.5::el8	automation-eda-controller-base-services	before 0:1.1.21-1.el8ap	0:1.1.21-1.el8ap
Red Hat:ansible_automation_platform:2.5::el8	automation-eda-controller-event-stream-services	before 0:1.1.21-1.el8ap	0:1.1.21-1.el8ap
Red Hat:ansible_automation_platform:2.5::el8	automation-eda-controller-worker-services	before 0:1.1.21-1.el8ap	0:1.1.21-1.el8ap
Red Hat:ansible_automation_platform:2.5::el8	automation-gateway-proxy	before 0:2.5.10-7.el8ap	0:2.5.10-7.el8ap
Red Hat:ansible_automation_platform:2.5::el8	automation-gateway-proxy-debugsource	before 0:2.5.10-7.el8ap	0:2.5.10-7.el8ap
Red Hat:ansible_automation_platform:2.5::el8	automation-gateway-proxy-server	before 0:2.5.10-7.el8ap	0:2.5.10-7.el8ap
Red Hat:ansible_automation_platform:2.5::el8	automation-gateway-proxy-server-debuginfo	before 0:2.5.10-7.el8ap	0:2.5.10-7.el8ap
Red Hat:ansible_automation_platform:2.5::el8	python3.12-aiohttp	before 0:3.14.1-2.el8ap	0:3.14.1-2.el8ap
Red Hat:ansible_automation_platform:2.5::el8	python3.12-daphne	before 0:4.2.2-1.el8ap	0:4.2.2-1.el8ap

+41

Same product

pyasn1: all records

Other highest-scoring records for the same primary product.

CVE-2026-119197pyasn1: Quadratic-complexity denial of service in binary REAL decoding
30Monitor
CVE-2026-119196pyasn1: Quadratic CPU consumption in constructed BIT STRING decoding
30Monitor
CVE-2026-119195pyasn1: Quadratic-time denial of service in constructed string and indefinite-length ANY decoding
30Monitor

Published before and after this one in the same product

← EarlierCVE-2026-30922Mar 18, 2026 · pyasn1 Vulnerable to Denial of Service via Unbounded Recursion
30Monitor
← EarlierCVE-2026-59884Jul 14, 2026 · pyasn1 BER/CER/DER decoder denial of service via unbounded long-form tag IDs
30Monitor
Later →CVE-2026-59886Jul 14, 2026 · pyasn1: Uncontrolled resource consumption when converting decoded REAL values
30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
pyasn1 pyasn1	0.6.4 · description	Vendor (CNA)
azl3 python-pyasn1 0.4.8-2 on Azure Linux 3.0	0.4.8-3 · CBL-Mariner Releases	Microsoft (MSRC)
debian:pyasn1	0.4.8-3+deb12u3 · Debian:12	Package registry (OSV)
opensuse:python-pyasn1	0.6.4-1.1 · openSUSE:Tumbleweed	Package registry (OSV)
PyPI:pyasn1	0.6.4	Package registry (OSV)
red hat:automation-eda-controller	0:1.1.21-1.el8ap · Red Hat:ansible_automation_platform:2.5::el8	Package registry (OSV)
red hat:automation-eda-controller-base	0:1.1.21-1.el8ap · Red Hat:ansible_automation_platform:2.5::el8	Package registry (OSV)
red hat:automation-eda-controller-base-services	0:1.1.21-1.el8ap · Red Hat:ansible_automation_platform:2.5::el8	Package registry (OSV)
red hat:automation-eda-controller-event-stream-services	0:1.1.21-1.el8ap · Red Hat:ansible_automation_platform:2.5::el8	Package registry (OSV)
red hat:automation-eda-controller-worker-services	0:1.1.21-1.el8ap · Red Hat:ansible_automation_platform:2.5::el8	Package registry (OSV)
red hat:automation-gateway-proxy	0:2.5.10-7.el8ap · Red Hat:ansible_automation_platform:2.5::el8	Package registry (OSV)
red hat:automation-gateway-proxy-debugsource	0:2.5.10-7.el8ap · Red Hat:ansible_automation_platform:2.5::el8	Package registry (OSV)
red hat:automation-gateway-proxy-server	0:2.5.10-7.el8ap · Red Hat:ansible_automation_platform:2.5::el8	Package registry (OSV)
red hat:automation-gateway-proxy-server-debuginfo	0:2.5.10-7.el8ap · Red Hat:ansible_automation_platform:2.5::el8	Package registry (OSV)
red hat:jaeger	0:2.19.0-1.1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:python3.12-aiohttp	0:3.14.1-2.el8ap · Red Hat:ansible_automation_platform:2.5::el8	Package registry (OSV)
red hat:receptor	0:1.6.7-1.el8ap · Red Hat:ansible_automation_platform_developer:2.5::el8	Package registry (OSV)
suse:python-pyasn1	0.6.1-160000.5.1 · SUSE:Linux Micro 6.2	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

pyasn1/pyasn1commit 45bdb19

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-598840 days apartpyasn1 BER/CER/DER decoder denial of service via unbounded long-form tag IDs
30Monitor
CVE-2026-598860 days apartpyasn1: Uncontrolled resource consumption when converting decoded REAL values
30Monitor

Not on record for this CVE: researcher credit · public bounty program.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-secondary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Endpoint Denial of ServiceT1499

Change log (1)

Fix✗ → ✓Sep 28, 2026, 10:46 PM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/pyasn1/pyasn1/commit/45bdb19eb7df4b3780fe9c912c63e99bffc39dd9

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records