CVE-2023-29400: Improper handling of empty HTML attributes in html/template
Vulnerability summary
CVE-2023-29400 is a high (CVSS 7.3) vulnerability in go standard library html/template. EPSS estimates a 1.04% chance of exploitation in the next 30 days, higher than 63.9% of scored vulnerabilities.
Severe, CVSS 7.3 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 23 · Related 10Timeline
- 11-05-2023PublishedVulnerability first disclosed.
- 24-01-2025Last modifiedVulnerability information updated.
Description
Templates containing actions in unquoted HTML attributes (e.g. "attr={{.}}") executed with empty input can result in output with unexpected results when parsed due to HTML normalization rules. This may allow injection of arbitrary attributes into tags.
CVSS metrics
7 scores · 7 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- OSV · DebianEcosystem advisory · calculated7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- OSV · WolfiEcosystem advisory · calculated7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- OSV · ChainguardEcosystem advisory · calculated7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- NVDNIST7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- OSV · AlpineEcosystem advisory · calculated7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS trend
Probability
1.04%
Chance of exploitation in the next 30 days
Percentile
64%
Versus all other CVEs
30-day change
No change 0.00 pp
From 1.04% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream ComponentThe product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
- CWE-94Improper Control of Generation of CodeThe product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Chainguard11 products
- go-1.20< 1.20.4-r0
- katib-earlystopping< 0.19.0-r31
- katib-suggestion-goptuna-compat< 0.19.0-r40
- katib-suggestion-hyperband< 0.19.0-r31
- katib-suggestion-hyperopt< 0.19.0-r31 | < 0.19.0-r40
Wolfi11 products
- go-1.20< 1.20.4-r0
- katib-earlystopping< 0.19.0-r31
- katib-suggestion-goptuna-compat< 0.19.0-r40
- katib-suggestion-hyperband< 0.19.0-r31
- katib-suggestion-hyperopt< 0.19.0-r31 | < 0.19.0-r40
Alpine1 product
- go≥ 1.20.0, < 1.19.9-r0 | ≥ 1.20.0, < 1.20.4-r0
Debian1 product
- golang-1.19All versions (No fix recorded)
Go1 product
- stdlib≥ 1.20.0-0, < 1.20.4
Go standard library1 product
- html/template< 1.19.9 | ≥ 1.20.0-0, < 1.20.4
Golang1 product
- go< 1.19.9 | ≥ 1.20.0, < 1.20.4
Ubuntu1 product
- golang-1.20< 1.20.3-1ubuntu0.1~20.04 | < 1.20.3-1ubuntu0.1~22.04
8 vendors · 28 products
References
16 linksShow all 16 references
- pkg.go.devWEB
