VulnerabilityPublished 19 Feb 2026

CVE-2026-26315: go-ethereum · Observable Discrepancy

Affects go-ethereumSource CVE Database V5

Not known to be exploited · CVSS 6.9 Medium : upgrade to 1.16.9 when convenient.

Data as of 26 Oct 2026, 09:08 UTC

CVSS 4.0 base score

6.9Medium

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.16.9

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 19 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC 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 go-ethereum to 1.16.9.

Affected software

Product	Affected	Fixed in
ethereumgo-ethereum	Affected <1.16.9	Fixed in 1.16.9

AI-suggested

To mitigate this vulnerability, organizations should promptly upgrade all go-ethereum (Geth) nodes to version 1.16.9 or later, where the ECIES flaw is fixed. After upgrading, it is essential to rotate the node's p2p key by deleting the existing nodekey file located at <datadir>/geth/nodekey before restarting the node. This ensures that any potentially leaked key material is invalidated and replaced with a new secure key. Network monitoring should be enhanced to detect unusual p2p connection patterns or node impersonation attempts. Operators should also review their node access controls and isolate critical nodes to limit exposure. Regularly auditing node software versions and cryptographic configurations will help prevent similar vulnerabilities. Finally, maintaining backups and incident response plans specific to blockchain infrastructure will aid in rapid recovery if exploitation occurs.

Description

go-ethereum (Geth) is a golang execution layer implementation of the Ethereum protocol. Prior to version 1.16.9, through a flaw in the ECIES cryptography implementation, an attacker may be able to extract bits of the p2p node key. The issue is resolved in the v1.16.9 and v1.17.0 releases of Geth. Geth maintainers recommend rotating the node key after applying the upgrade, which can be done by removing the file `<datadir>/geth/nodekey` before starting Geth.

Impact

The primary impact of this vulnerability is the potential compromise of the confidentiality and integrity of Ethereum node communications. By extracting bits of the p2p node key, attackers can impersonate legitimate nodes or intercept and manipulate network traffic. This can lead to network partitioning, disruption of consensus mechanisms, or targeted attacks on specific nodes. For organizations running Ethereum infrastructure, such as exchanges, DeFi platforms, or blockchain service providers, this could result in service outages, loss of trust, or financial damage. The vulnerability does not directly affect the blockchain ledger but undermines the security of the network layer, which is critical for reliable operation. Since exploitation requires no authentication and can be performed remotely, the attack surface is broad. However, the absence of known exploits in the wild and the availability of patches reduce immediate risk. Nonetheless, failure to upgrade and rotate keys could expose organizations to medium-level threats that degrade network security and reliability.

CWE-203Observable Discrepancy (opens in a new tab)
Base weakness
The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
Implementation
Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended).
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Black Box Reverse Engineering (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/ethereum/go-ethereum/security/advisories/GHSA-m6j8-rg6r-7mv8 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 28 Feb 2026, 14:46 UTC

WeaknessesCWE-203

Technical details

References

Community reviews

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