CVE-2008-4128
CVE-2008-4128 is a security flaw in Cisco IOS, the operating system on Cisco’s routers and switches. Attackers can run commands on Cisco IOS. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 13 Jul 2026.[1]
Cisco IOS is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Cisco has published a fix or advice.
Description
CISA calls it a cross-site request forgery in Cisco IOS. In its words: “Cisco IOS 12.4 contains multiple cross-site forgery vulnerabilities that allows remote attackers to execute arbitrary commands via (1) a certain "show privilege" command to the /level/15/exec/- URI, and (2) a certain "alias exec" command to the /level/15/exec/-/configure/http URI.”[1]
The CVE record adds: “Multiple cross-site request forgery (CSRF) vulnerabilities in the HTTP Administration component in Cisco IOS 12.4 on the 871 Integrated Services Router allow remote attackers to execute arbitrary commands via (1) a certain "show privilege" command to the /level/15/exec/- URI, and (2) a certain "alias exec" command to the /level/15/exec/-/configure/http URI. NOTE: some of these details are obtained from third party information.”[2]
The underlying weakness is cross-site request forgery (CWE-352), in MITRE’s list of common software weaknesses.
It scores 8.1 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by the organisation that published the CVE using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Cisco’s advisory has them[3]. CISA names the product as Cisco IOS.
Most families won’t have Cisco IOS; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 13 Jul 2026, 6,507 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 16 Jul 2026 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 34%. That’s in the top 2% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Cisco has published a fix or advice.[3] CISA’s required action: “Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes).”[1]
- Check whether you use it.Cisco IOS is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 16 Jul 2026 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 8.1.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 34%.[4] |
See also
Other Cisco IOS flaws
- CVE-2004-1464: denial-of-service ·
Other Cisco flaws
- CVE-2026-76418, Cisco Secure Firewall ASA Software and Cisco Secure FTD Software: unchecked return value to NULL pointer dereference ·
- CVE-2026-76519, Cisco Secure Email Gateway: relative path traversal ·
- CVE-2026-76504, Cisco Catalyst SD-WAN Manager: hex encoding ·
- CVE-2026-76460, Cisco Identity Services Engine: incorrect use of privileged APIs ·
- CVE-2026-76461, Cisco Secure Email Gateway: SQL injection ·
Other cross-site request forgery flaws
- CVE-2023-2533, PaperCut NG/MF: cross-site request forgery (CSRF) ·
- CVE-2014-100005, D-Link DIR-600 Router: cross-site request forgery (CSRF) ·
- CVE-2016-6277, NETGEAR Multiple Routers: remote code execution ·
- CVE-2020-10181, Sumavision Enhanced Multimedia Router (EMR): EMR cross-site request forgery (CSRF) ·
Every Cisco flaw on CISA’s list · Everything added in July 2026
References
- ^ Cybersecurity and Infrastructure Security Agency. “Cisco IOS Cross-Site Request Forgery Vulnerability”. Known Exploited Vulnerabilities Catalog, added 13 Jul 2026.
- ^ National Institute of Standards and Technology. “CVE-2008-4128 Detail”. National Vulnerability Database, published 18 Sep 2008.
- ^ Cisco. Advisories and fixes: cisco.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.339, percentile 98.4, 31 Oct 2026.
- CVE Program. “CVE-2008-4128”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.