A vulnerability in the web-based management interface of multiple Cisco Small Business Series Switches could allow an unauthenticated, remote attacker to replay valid user session credentials and gain unauthorized access to the web-based management interface of an affected device. This vulnerability is due to insufficient expiration of session credentials. An attacker could exploit this vulnerability by conducting a man-in-the-middle attack against an affected device to intercept valid session credentials and then replaying the intercepted credentials toward the same device at a later time. A successful exploit could allow the attacker to access the web-based management interface with administrator privileges.
Conclusion & alert: CVE-2021-34739 is rated Moderate Risk (59/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.62%). Core evidence: EPSS rose +1.12% over the last day, indicating growing attacker interest. Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.50% | 1.62% | +1.12% |
| 2 | 2025-11-21 | 0.70% | 0.50% | -0.20% |
| 3 | 2025-11-18 | — | 0.70% | — |
Full EPSS history (15 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.1 | 3.1 | HIGH |
|
2.2 | 5.9 | [email protected] |
| 8.1 | 3.1 | HIGH |
|
2.2 | 5.9 | [email protected] |
| 6.8 | 2.0 | MEDIUM |
|
8.6 | 6.4 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| cisco | sf250-24_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-24_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-24p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-24p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-48_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-48_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-48hp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-48hp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-08_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-08_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-08hp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-08hp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-10p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-10p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-18_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-18_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-26_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-26_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-26hp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-26hp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-26p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-26p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-50_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-50_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-50hp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-50hp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250-50p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250-50p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250x-24_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250x-24_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250x-24p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250x-24p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250x-48_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250x-48_firmware:*:*:*:*:*:*:*:* |
| cisco | sf250x-48p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf250x-48p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-08_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-08_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-24_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-24_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-24mp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-24mp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-24p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-24p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-48_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-48_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-8mp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-8mp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-48p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-48p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf352-08_firmware | <= 2.5 | cpe:2.3:o:cisco:sf352-08_firmware:*:*:*:*:*:*:*:* |
| cisco | sf352-08mp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf352-08mp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf352-08p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf352-08p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-8pd_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-8pd_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-10_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-10_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-10mp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-10mp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-10p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-10p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-10sfp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-10sfp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-20_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-20_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-28_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-28_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-28mp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-28mp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-28p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-28p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-28sfp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-28sfp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-52_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-52_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-52mp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-52mp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf350-52p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf350-52p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf355-10p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf355-10p_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350x-8pmd_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350x-8pmd_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350x-12pmv_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350x-12pmv_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350x-24_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350x-24_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350x-24p_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350x-24p_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350x-24mp_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350x-24mp_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350x-24pd_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350x-24pd_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350x-24pv_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350x-24pv_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350x-48_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350x-48_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350x-48p_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350x-48p_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350x-48mp_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350x-48mp_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350x-48pv_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350x-48pv_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350xg-2f10_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350xg-2f10_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350xg-24f_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350xg-24f_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350xg-24t_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350xg-24t_firmware:*:*:*:*:*:*:*:* |
| cisco | sg350xg-48t_firmware | <= 2.5 | cpe:2.3:o:cisco:sg350xg-48t_firmware:*:*:*:*:*:*:*:* |
| cisco | sx350x-08_firmware | <= 2.5 | cpe:2.3:o:cisco:sx350x-08_firmware:*:*:*:*:*:*:*:* |
| cisco | sx350x-12_firmware | <= 2.5 | cpe:2.3:o:cisco:sx350x-12_firmware:*:*:*:*:*:*:*:* |
| cisco | sx350x-24f_firmware | <= 2.5 | cpe:2.3:o:cisco:sx350x-24f_firmware:*:*:*:*:*:*:*:* |
| cisco | sx350x-24_firmware | <= 2.5 | cpe:2.3:o:cisco:sx350x-24_firmware:*:*:*:*:*:*:*:* |
| cisco | sx350x-52_firmware | <= 2.5 | cpe:2.3:o:cisco:sx350x-52_firmware:*:*:*:*:*:*:*:* |
| cisco | sf550x-24_firmware | <= 2.5 | cpe:2.3:o:cisco:sf550x-24_firmware:*:*:*:*:*:*:*:* |
| cisco | sf550x-24p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf550x-24p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf550x-24mp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf550x-24mp_firmware:*:*:*:*:*:*:*:* |
| cisco | sf550x-48_firmware | <= 2.5 | cpe:2.3:o:cisco:sf550x-48_firmware:*:*:*:*:*:*:*:* |
| cisco | sf550x-48p_firmware | <= 2.5 | cpe:2.3:o:cisco:sf550x-48p_firmware:*:*:*:*:*:*:*:* |
| cisco | sf550x-48mp_firmware | <= 2.5 | cpe:2.3:o:cisco:sf550x-48mp_firmware:*:*:*:*:*:*:*:* |
| cisco | sg550x-24_firmware | <= 2.5 | cpe:2.3:o:cisco:sg550x-24_firmware:*:*:*:*:*:*:*:* |
| cisco | sg550x-24p_firmware | <= 2.5 | cpe:2.3:o:cisco:sg550x-24p_firmware:*:*:*:*:*:*:*:* |
| cisco | sg550x-24mp_firmware | <= 2.5 | cpe:2.3:o:cisco:sg550x-24mp_firmware:*:*:*:*:*:*:*:* |
| cisco | sg550x-24mpp_firmware | <= 2.5 | cpe:2.3:o:cisco:sg550x-24mpp_firmware:*:*:*:*:*:*:*:* |
| cisco | sg550x-48_firmware | <= 2.5 | cpe:2.3:o:cisco:sg550x-48_firmware:*:*:*:*:*:*:*:* |
| cisco | sg550x-48p_firmware | <= 2.5 | cpe:2.3:o:cisco:sg550x-48p_firmware:*:*:*:*:*:*:*:* |
| cisco | sg550x-48mp_firmware | <= 2.5 | cpe:2.3:o:cisco:sg550x-48mp_firmware:*:*:*:*:*:*:*:* |
| cisco | sg550xg-8f8t_firmware | <= 2.5 | cpe:2.3:o:cisco:sg550xg-8f8t_firmware:*:*:*:*:*:*:*:* |
| cisco | sg550xg-24f_firmware | <= 2.5 | cpe:2.3:o:cisco:sg550xg-24f_firmware:*:*:*:*:*:*:*:* |
| cisco | sg550xg-24t_firmware | <= 2.5 | cpe:2.3:o:cisco:sg550xg-24t_firmware:*:*:*:*:*:*:*:* |
| cisco | sg550xg-48t_firmware | <= 2.5 | cpe:2.3:o:cisco:sg550xg-48t_firmware:*:*:*:*:*:*:*:* |
| cisco | sx550x-12f_firmware | <= 2.5 | cpe:2.3:o:cisco:sx550x-12f_firmware:*:*:*:*:*:*:*:* |