CVE-2023-29405Network attack vector

Arbitrary code execution via smuggled linker flags

Published Jun 8, 2023 · Updated Jan 6, 2025

Linker-flag injection in Go cmd/go and cmd/cgo before 1.19.10 and 1.20.0 through 1.20.4 allows attackers to execute code during builds. With gccgo, embedded spaces in a #cgo LDFLAGS argument let a disallowed linker option pass sanitization as part of another option's argument. Execution requires building attacker-controlled code with cgo and gccgo, including fetching a malicious module, and runs with the builder's privileges.

CVSS severity9.8
Critical
EPSS probability1.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Linker-flag injection in Go cmd/go and cmd/cgo before 1.19.10 and 1.20.0 through 1.20.4 allows attackers to execute code during builds. With gccgo, embedded spaces in a #cgo LDFLAGS argument let a disallowed linker option pass sanitization as part of another option's argument. Execution requires building attacker-controlled code with cgo and gccgo, including fetching a malicious module, and runs with the builder's privileges.

The record

CVE
CVE-2023-29405
Published
Jun 8, 2023
Updated
Jan 6, 2025
Vendor
Go
Product
Go command
Classifications
CWE-74, T1195.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 6, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.19.10
  2. Affected versionversion=1.20.0-0 <1.20.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Go · Go commandversion=0 <1.19.10; version=1.20.0-0 <1.20.5
Go · cmd/cgoversion=0 <1.19.10; version=1.20.0-0 <1.20.5

Published CVSS scores

9.8NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
T1195.001Compromise Software Dependencies and Development Tools

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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