CVE-2020-26258

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

81.81% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 99.6% of scored records. A rank, not a probability.

NVD base score

7.7 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

NVD analysis status

Analyzed. NVD last modified this record on 2026-10-07.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2020-12-16 01:05Z5 YR AGO

Last updated

2026-10-07 18:41Z21 DAYS AGO

Reserved

2020-10-01

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

Medium (CVSS 6.3)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Weaknesses

• CWE-918Server-Side Request Forgery (SSRF)Base

Data version

5.2

Document digest

3ac50d5eafc1a29965fb6bdb36bf3d7c968688f8056bf458c42e2e1191f23f01

• github.comhttps://github.com/x-stream/xstream/security/advisories/GHSA-4cch-wxpw-8p28x_refsource_CONFIRM
• lists.apache.orghttps://lists.apache.org/thread.html/r97993e3d78e1f5389b7b172ba9f308440830ce5f051ee62714a0aa34@%3Ccommits.struts.apache.org%3Ex_refsource_MISC
• lists.debian.orghttps://lists.debian.org/debian-lts-announce/2020/12/msg00042.htmlx_refsource_MISC
• lists.fedoraproject.orghttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHPx_refsource_MISC
• lists.fedoraproject.orghttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7x_refsource_MISC
• lists.fedoraproject.orghttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREBx_refsource_MISC
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20210409-0005x_refsource_MISC
• www.debian.orghttps://www.debian.org/security/2021/dsa-4828x_refsource_MISC
• x-stream.github.iohttps://x-stream.github.io/CVE-2020-26258.htmlx_refsource_MISC
• lists.apache.org[struts-commits] 20201221 [struts] branch master updated: Upgrades XStream to version 1.4.15 to address CVE-2020-26258, CVE-2020-26259https://lists.apache.org/thread.html/r97993e3d78e1f5389b7b172ba9f308440830ce5f051ee62714a0aa34%40%3Ccommits.struts.apache.org%3Emailing-listx_refsource_MLIST
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20210409-0005/x_refsource_CONFIRM
• lists.fedoraproject.orgFEDORA-2021-fbad11014ahttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP/vendor-advisoryx_refsource_FEDORA
• lists.fedoraproject.orgFEDORA-2021-d894ca87dchttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB/vendor-advisoryx_refsource_FEDORA
• lists.fedoraproject.orgFEDORA-2021-5e376c0ed9https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7/vendor-advisoryx_refsource_FEDORA