VulnerabilityPublished 29 Sep 2026Updated 30 Sep 2026

CVE-2026-102521: dmonad lib0 · Out-of-bounds Read

Affects dmonad lib0Source CVE Database V5

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Not known to be exploited · CVSS 8.6 High.

Data as of 12 Nov 2026, 23:24 UTC

CVSS 3.1 base score

8.6High

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 17% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: None
Availability: None

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: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 29 Sep 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 13 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

Affected software

Product	Affected	Fixed in
dmonadlib0	Affected <=0.2.118	Fixed in–
GitHubdmonad/lib0`pkg:github/dmonad/lib0`Other threats	Affected <=0.2.118	Fixed in–

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

AI-suggested

Until an official fix is available, users should consider avoiding use of affected versions (<=0.2.118) or applying any available workarounds recommended by the vendor. Monitor official dmonad project channels for updates and patches addressing this issue.

Description

CVE-2026-102521 is a high-severity out-of-bounds read vulnerability in the decoder function `readFromDataView` of the dmonad lib0 library versions up to 0.2.118. The flaw allows the decoder to read beyond its intended buffer boundaries, potentially exposing adjacent process memory such as credentials or logs. This vulnerability does not affect integrity or availability but can lead to information disclosure. It is similar to a previously known issue (GHSA-r5c8-rf4w-qrq8) but distinct in its specifics. No known exploits are reported in the wild, and no official patch or remediation details are provided in the input data.

Impact

Successful exploitation of this vulnerability can lead to unauthorized disclosure of sensitive information from adjacent memory regions in the affected process. This could include credentials or logs that reside in memory near the buffer being decoded. There is no indication of impact on integrity or availability. The vulnerability can be exploited remotely without authentication or user interaction, increasing its risk profile.

Summary

The vulnerability exists in the `readFromDataView` decoder function of dmonad's lib0 library before version 0.2.119. It allows an attacker to cause an out-of-bounds read by tricking the decoder into reading more data than it should from a buffer. This results in exposure of adjacent memory contents within the process, which may include sensitive information such as credentials or logs. The CVSS v3.1 base score is 8.6, indicating a high severity with network attack vector, low attack complexity, no privileges or user interaction required, and a confidentiality impact rated as high. The vulnerability affects all versions up to and including 0.2.118. There is no vendor advisory or patch link provided, and no known exploits have been reported.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
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 · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Oct 2026, 20:39 UTC

WeaknessesCWE-125

Technical details

References

Community reviews

Related threats