CVE-2026-94300: Concurrent GSS-TSIG messages corrupt memory
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 1%
Up from 0.7% on .
EPSS score, percentile 61.3 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 8.1 High
CVSS v3.1 base score, given by the CNA
- What should I do?
Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.30, 9.21.27, or 9.20.30-S1.Solution from the CVE record.
CISA has set no required action, because the vulnerability is not in KEV.
- Which versions are affected?
Affected
- 9.11.0 through 9.18.50
- 9.20.0 through 9.20.29
- 9.21.0 through 9.21.26
- 9.11.3-S1 through 9.18.50-S1
- 9.20.9-S1 through 9.20.29-S1
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Solution (from the CVE record)
Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.30, 9.21.27, or 9.20.30-S1.
Workaround (from the CVE record)
No workarounds known.
Advisories and patches
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | 9.11.0 through 9.18.50 |
| Affected | 9.20.0 through 9.20.29 |
| Affected | 9.21.0 through 9.21.26 |
| Affected | 9.11.3-S1 through 9.18.50-S1 |
| Affected | 9.20.9-S1 through 9.20.29-S1 |
Versions not listed are: unaffected.
Source: CVE List, as of . About the data.
About this vulnerability
Replaying GSS-TSIG signed UDP messages can result in memory corruption in "`named`". An attacker who can capture a previously signed UDP message can replay it while the negotiated TSIG key is still valid. By also sending crafted queries to a zone the attacker controls, the attacker may potentially achieve remote code execution. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 th…
Summary: CVE record, as of .
- CISA has not added CVE-2026-94300 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 21 Oct 2026.
- The CVE record carries a CVSS v3.1 base score of 8.1 (High), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 1% (percentile 61.3), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact total.
- The credits in the CVE record name OpenAI as finder.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
Concurrent GSS-TSIG messages corrupt memory
Replaying GSS-TSIG signed UDP messages can result in memory corruption in "`named`". An attacker who can capture a previously signed UDP message can replay it while the negotiated TSIG key is still valid. By also sending crafted queries to a zone the attacker controls, the attacker may potentially achieve remote code execution. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.29, 9.21.0 through 9.21.26, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.29-S1.
Source: CVE List, as of . About the data.
Weakness
CWE-415, CWE-362
- CWE-415: Double Free
- CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition)
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |
Known exploited ISC vulnerabilities
- CVE-2015-5477: ISC BIND Data Processing Errors Vulnerability