CVE-2020-26258
In XStream before version 1.4.15, a Server-Side Forgery Request vulnerability can be activated when unmarshalling.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 81.8%, higher than 100% of all known CVEs. Patch or mitigate before the next change window.
Description
XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.15, a Server-Side Forgery Request vulnerability can be activated when unmarshalling. The vulnerability may allow a remote attacker to request data from internal resources that are not publicly available only by manipulating the processed input stream. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.15. The reported vulnerability does not exist if running Java 15 or higher. No user is affected who followed the recommendation to setup XStream's Security Framework with a whitelist! Anyone relying on XStream's default blacklist can immediately switch to a whilelist for the allowed types to avoid the vulnerability. Users of XStream 1.4.14 or below who still want to use XStream default blacklist can use a workaround described in more detailed in the referenced advisories.
- CVSS 3.1
- 7.7 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
- EPSS
- 81.82% probability · 100th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-918
- Affected
- apache/struts · xstream/xstream · debian/debian linux · fedoraproject/fedora
- Source
- security-advisories@github.com
EPSS 81.8% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/x-stream/xstream/security/advisories/GHSA-4cch-wxpw-8p28Mitigation, Third Party Advisory
- https://lists.apache.org/thread.html/r97993e3d78e1f5389b7b172ba9f308440830ce5f051ee62714a0aa34@%3Ccommits.struts.apache.org%3EIssue Tracking, Mailing List
- https://lists.debian.org/debian-lts-announce/2020/12/msg00042.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHPMailing List
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7Mailing List
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREBMailing List
- https://security.netapp.com/advisory/ntap-20210409-0005Third Party Advisory
- https://www.debian.org/security/2021/dsa-4828Third Party Advisory
- https://x-stream.github.io/CVE-2020-26258.htmlExploit, Mitigation, Third Party Advisory
- https://github.com/x-stream/xstream/security/advisories/GHSA-4cch-wxpw-8p28Mitigation, Third Party Advisory
- https://lists.apache.org/thread.html/r97993e3d78e1f5389b7b172ba9f308440830ce5f051ee62714a0aa34%40%3Ccommits.struts.apache.org%3EIssue Tracking, Mailing List
- https://lists.debian.org/debian-lts-announce/2020/12/msg00042.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP/Mailing List
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7/Mailing List
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB/Mailing List
- https://security.netapp.com/advisory/ntap-20210409-0005/Third Party Advisory
- https://www.debian.org/security/2021/dsa-4828Third Party Advisory
- https://x-stream.github.io/CVE-2020-26258.htmlExploit, Mitigation, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.