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Public proof of conceptFix available

CVE-2026-30922

A public proof of concept exists; no exploitation attested.

  • Published2026-03-18
  • Fixed in0.6.3
  • WeaknessCWE-674 · CWE-835

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.3, the `pyasn1` library is vulnerable to a Denial of Service (DoS) attack caused by uncontrolled recursion when decoding ASN.1 data with deeply nested structures. An attacker can supply a crafted payload containing thousands of nested `SEQUENCE` (`0x30`) or `SET` (`0x31`) tags with "Indefinite Length" (`0x80`) markers. This forces the decoder to recursively call itself until the Python interpreter crashes with a `RecursionError` or consumes all available memory (OOM), crashing the host application. This is a distinct vulnerability from CVE-2026-23490 (which addressed integer overflows in OID decoding). The fix for CVE-2026-23490 (`MAX_OID_ARC_CONTINUATION_OCTETS`) does not mitigate this recursion issue. Version 0.6.3 fixes this specific issue.

Timeline

dates in UTC
  1. 2026-03-1804:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-30922?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-30922?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV
Pyasn1
BranchAffectedFixed in
0.6< 0.6.30.6.3

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • fence-agents-apcAlmaLinux:10all versions · fixed in 4.16.0-13.el10_1.4and 35 other packages
  • fence-agents-apcAlmaLinux:8all versions · fixed in 4.2.1-129.el8_10.25and 47 other packages
  • fence-virtdAlmaLinux:9all versions · fixed in 4.10.0-98.el9_7.13and 55 other packages
  • resource-agentsAlmaLinux:8all versions · fixed in 4.9.0-54.el8_10.33and 3 other packages

Vendor advisories

  • RHSA-2026:37275 Red Hat Product Security33 products fixed

    Red Hat Security Advisory: RHOAI 3.3.5 - Red Hat OpenShift AI

  • RHSA-2026:24761 Red Hat Product Security8 products fixed

    Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.5 Product Security and Bug Fix Update

  • RHSA-2026:24762 Red Hat Product Security12 products fixed

    Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.6 Product Security and Bug Fix Update

  • RHSA-2026:19712 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: RHOAI 3.3.3 - Red Hat OpenShift AI

  • RHSA-2026:19355 Red Hat Product Security96 products fixed

    Red Hat Security Advisory: fence-agents security update

  • RHSA-2026:19375 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: Red Hat Quay 3.16.4

10 more advisories

Full record on NVD

Fix

  1. Update Pyasn1 to 0.6.3
  2. Vendor fix Red Hat Product Security RHSA-2026:37275 · 33 productsFor Red Hat OpenShift AI 3.3.5 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/red_hat_openshift_ai/
  3. Vendor fix Red Hat Product Security RHSA-2026:24761 · 8 productsFor details on how to apply this update, refer to Ansible Automation Platform documentation.
  4. Vendor fix Red Hat Product Security RHSA-2026:19712 · 4 productsFor Red Hat OpenShift AI 3.3.3 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/red_hat_openshift_ai/
  5. Vendor fix Red Hat Product Security RHSA-2026:19355 · 96 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  6. Vendor fix Red Hat Product Security RHSA-2026:19375 · 4 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
  7. Vendor fix Red Hat Product Security RHSA-2026:14020 · 3 productsThe Service Telemetry Framework container image provided by this update can be downloaded from the Red Hat Container Registry at registry.access.redhat.com. Installation instructions for your platform are available at Red Hat Container Catalog (see References). Dockerfiles and scripts should be am…

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVE recordread 2026-10-23
  • CISA-ADPSSVC decisionpoc2026-03-18
  • OpenCVESSVC decisionpoc—
  • CNACVSS 3.17.5read 2026-10-23
  • CNAweakness (CWE)CWE-674, CWE-835read 2026-10-23
  • FIRST EPSSEPSS score1.0 %2026-10-22
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2026-03-18
Last Modified
2026-09-10
NVD status
Modified

Frequently asked questions

What is CVE-2026-30922?

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.3, the `pyasn1` library is vulnerable to a Denial of Service (DoS) attack caused by uncontrolled recursion when decoding ASN.1 data with deeply nested structures. An attacker can supply a crafted payload containing thousands of nested `SEQUENCE` (`0x30`) or `SET` (`0x31`) tags with "Indefinite Length" (`0x80`) markers. This forces the decoder to recursively call itself until the Python interpreter crashes with a `RecursionError` or consumes all available memory (OOM), crashing the host application. This is a distinct vulnerability from CVE-2026-23490 (which addressed integer overflows in OID decoding). The fix for CVE-2026-23490 (`MAX_OID_ARC_CONTINUATION_OCTETS`) does not mitigate this recursion issue. Version 0.6.3 fixes this specific issue.

Is CVE-2026-30922 actively exploited?

A proof-of-concept exploit exists for CVE-2026-30922, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-30922?

CVE-2026-30922 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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