No exploitation reportedFix available

CVE-2021-29999

Q: Is CVE-2021-29999 actively exploited?

Active exploitation of CVE-2021-29999 has not been confirmed. Its EPSS score was 1.8% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-29999?

CVE-2021-29999 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2021-04-13
WeaknessCWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

An issue was discovered in Wind River VxWorks through 6.8. There is a possible stack overflow in dhcp server.

Timeline

dates in UTC

2021-04-1317:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-29999?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-29999?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Windriver vxworks

Branch	Affected	Fixed in	Source
6.8	≤ 6.8	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

ICSA-25-058-01 CISA6 known affected
Schneider Electric communication modules for Modicon M580 and Quantum controllers (Update B)
Schneider Electric Modicon M580 communication modules BMENOC BMENOC0321: <SV1.10 · Schneider Electric Modicon M580 communication modules BMECRA BMECRA31210: <SV02.80 · Schneider Electric Modicon M580/Quantum communication modules BMXCRA BMXCRA31200: <SV02.80 · +3 more

Full record on NVD

Fix

Vendor fix CISA ICSA-25-058-01 · 1 productModicon M580 communication modules BMENOC BMENOC0321: Version SV1.10 of BMENOC0321 includes a fix for this vulnerability and is available for download.
Vendor fix CISA ICSA-25-058-01 · 2 productsModicon M580 communication modules BMECRA BMECRA31210, Modicon M580/Quantum communication modules BMXCRA BMXCRA31200/BMXCRA31210: Version SV02.80 of BMECRA31210, BMXCRA31200, BMXCRA31210 includes a fix for these vulnerabilities and is available for download.
Mitigation from the vendor CISA ICSA-25-058-01 · 6 productsSchneider Electric has identified the following specific remediations and mitigations users can apply to reduce risk:
Mitigation from the vendor CISA ICSA-25-058-01 · 6 products140CRA31200 (Quantum RIO Drop): Version V02.80 of 140CRA31200 includes a fix for these vulnerabilities and is available for download.
Mitigation from the vendor CISA ICSA-25-058-01 · 6 products140CRA31908 (M580 Quantum S908 RIO Drop Adapter): Version V02.80 of 140CRA31908 includes a fix for these vulnerabilities and is available for download.
Mitigation from the vendor CISA ICSA-25-058-01 · 6 productsSchneider Electric strongly recommends the following industry cybersecurity best practices:

Advisories and patches

support2.windriver.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
NVDweakness (CWE)CWE-787read 2026-10-23
FIRST EPSSEPSS score1.8 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2021-04-13
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-29999?

An issue was discovered in Wind River VxWorks through 6.8. There is a possible stack overflow in dhcp server.

Is CVE-2021-29999 actively exploited?

Active exploitation of CVE-2021-29999 has not been confirmed. Its EPSS score was 1.8% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-29999?

CVE-2021-29999 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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