VulnerabilityPublished 13 Aug 2026Updated 31 Oct 2026

CVE-2026-30922: Mcp google sheets · Denial of Service in pyasn1 via Unbounded Recursion

Affects mcp-google-sheetsSource GCVE Database

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Not known to be exploited · CVSS 7.5 High : upgrade to 0.6.1_1 soon.

Data as of 1 Nov 2026, 01:52 UTC

CVSS 3.0 base score

7.5High

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

Patch: Available – fixed in 0.6.1_1

CVSS:3.0/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 13 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 31 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 mcp-google-sheets to 0.6.1_1.

Patches and advisories

Affected software

Product	Affected	Fixed in
Homebrewmcp-google-sheets`pkg:brew/mcp-google-sheets`Other threats	Affected >=0.5.1 <0.6.1_1	Fixed in 0.6.1_1

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

AI-suggested

A patch is available in pyasn1 version 0.6.1_1 that addresses this unbounded recursion issue. Users should upgrade to this fixed version to remediate the vulnerability. No other mitigations are indicated by the vendor advisory.

Description

The pyasn1 library contains a vulnerability that allows an attacker to cause a Denial of Service (DoS) by supplying ASN.1 data with deeply nested indefinite-length SEQUENCE or SET tags. This triggers unbounded recursion in the decoder, leading to a RecursionError or out-of-memory crash. Services parsing untrusted ASN.1 data using pyasn1 are at risk of crashing or resource exhaustion. A patch is available in version 0.6.1_1.

Impact

The vulnerability allows remote attackers to cause a denial of service by crashing the service worker process or thread handling ASN.1 decoding. The attack can be triggered with a small payload (<100KB), causing either a RecursionError or out-of-memory condition, leading to service unavailability. In environments with increased recursion limits, the attack can exhaust server memory, causing broader impact. No confidentiality or integrity impacts are reported.

Summary

CVE-2026-30922 affects the pyasn1 library, where the BER decoder recursively processes ASN.1 data without limiting recursion depth. Specifically, indefinite-length constructed types and standard SEQUENCE/SET types are decoded via recursive calls to decodeFun without depth checks. An attacker can craft payloads with deeply nested indefinite-length SEQUENCE (0x30) or SET (0x31) tags, causing the decoder to recurse until the Python interpreter crashes with a RecursionError or exhausts memory. This vulnerability impacts any service using pyasn1 to parse untrusted ASN.1 data, such as LDAP, SNMP, Kerberos, or X.509 parsers. The issue is fixed in pyasn1 version 0.6.1_1.

References

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