At a glance
Actively exploited in the wild — prioritise confirming exposure.
Medium rather than High: exposure is scored at a default because we cannot see your systems or suppliers. If it touches your systems or suppliers, treat it as High.
Briefing
- Do not treat uncorroborated claims as confirmed breaches.
Questions to ask IT
- Are we affected by CVE-2021-21311, and which of our systems would be?
- Have we checked whether it has already been used against us?
- If it is not yet patched, what mitigation is in place, and will the fix be done by 11 Nov?
Next steps
- Confirm exposure, mitigation status and any service interruption risk.
Vulnerability facts
Full CVE detail CVE-2021-21311- 7.2 · HighExploitable over the network without any account, and no one has to click or open anything. Low impact on confidentiality and integrity, and it can reach beyond the vulnerable system.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- Listed: attacks using it have been seen (on the catalogue since )
- Elevated attack likelihood (~98.5% in 30 days)
- Before 4.7.9
- 4.7.9
Versions are as the CVE record states them; check the vendor advisory before planning a fix.
- CVE-2021-21311 has estimated attack likelihood 0.90461 (~90.5% estimated chance of exploitation in 30 days; 99.8th percentile) as of 2026-07-31 — probability signal, not confirmed exploitation
Next steps
- Confirm whether affected products/versions are present and prioritise patching or mitigations
Summary
- Adminer contains a server-side request forgery vulnerability that, when exploited, allows a remote attacker to obtain potentially sensitive information.
- CVE-2021-21311 is listed in known-exploited catalogue (exploitation in the wild)
- 5% estimated chance of exploitation in 30 days; 99.
- Authoritative catalogues report active exploitation of this vulnerability.
Why this matters in the UK
- Known-exploited catalogue reports exploitation in the wild
Pulse
Last checked 4d ago · Recheck overdue since 5 Nov 2026, 23:33 UK time · 3 quiet checks collapsed
Suggested changed to 7d.
Listed on the — prioritise confirming exposure and patching.
3 quiet checks hidden.
Sources
Adminer Server-Side Request Forgery Vulnerability
How we know
Statements extracted from sources. Higher confidence means stronger corroboration.
- ConfirmedHeadline90% confidence
Adminer Server-Side Request Forgery Vulnerability
- ConfirmedSummary fact75% confidence
Adminer contains a server-side request forgery vulnerability that, when exploited, allows a remote attacker to obtain potentially sensitive information. Affects Adminer Adminer. Known ransomware campaign use: Unknown. Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- ConfirmedCVE identifier95% confidence
Event involves CVE-2021-21311
- ConfirmedKnown-exploited catalogue98% confidence
CVE-2021-21311 is listed in known-exploited catalogue (exploitation in the wild)
- ConfirmedEstimated attack likelihood95% confidence
CVE-2021-21311 has estimated attack likelihood 0.90461 (~90.5% estimated chance of exploitation in 30 days; 99.8th percentile) as of 2026-07-31 — probability signal, not confirmed exploitation