Server-Side Forgery Request can be activated unmarshalling with XStream
Noroxi assessment
Priority: Plan (action score 55/100)
- A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 81.8% (FIRST EPSS); higher than 99.6% of all records.
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- According to CISA the attack is automatable: targets can be found by mass scanning.
- Fixed version: libxstream-java (Debian:10) 1.4.11.1-1+deb10u2; libxstream-java (Debian:12) 1.4.15-1; libxstream-java (Debian:9) 1.4.11.1-1+deb9u1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Add it to your regular patch cycle. Upgrade to libxstream-java (Debian:10) 1.4.11.1-1+deb10u2; libxstream-java (Debian:12) 1.4.15-1; libxstream-java (Debian:9) 1.4.11.1-1+deb9u1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- Published
- Dec 16, 2020
- Updated
- Oct 7, 2026
- EPSS
- 81.8% · 99th percentile
- CWE
- CWE-918
Report tools
Action score
55
Plan
Add it to your regular patch cycle.
- CVSS
- 30 / 40 · 7.7 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 25 / 30 · 81.8%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.7
- CNA · GitHub_M
- 6.3
- 1.4 point gap
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- Proof of concept exists, no weaponized module
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| xstream | xstream | cpe:2.3:a:xstream:xstream |
| apache | struts | cpe:2.3:a:apache:struts |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- apache strutsbefore 6.0.0
- debian debian linux10.0
- debian debian linux9.0
- fedoraproject fedora33
- fedoraproject fedora34
- fedoraproject fedora35
- xstream xstreambefore 1.4.15
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
x-stream xstream
- < 1.4.15affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:10 | libxstream-java | before 1.4.11.1-1+deb10u2 | 1.4.11.1-1+deb10u2 |
| Debian:12 | libxstream-java | before 1.4.15-1 | 1.4.15-1 |
| Debian:9 | libxstream-java | before 1.4.11.1-1+deb9u1 | 1.4.11.1-1+deb9u1 |
| Maven | com.thoughtworks.xstream:xstream | before 1.4.15 | 1.4.15 |
| openSUSE:Leap 15.2 | xstream | before 1.4.15-lp152.2.3.1 | 1.4.15-lp152.2.3.1 |
| openSUSE:Tumbleweed | xstream | before 1.4.18-1.1 | 1.4.18-1.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP2 | xstream | before 1.4.15-3.3.2 | 1.4.15-3.3.2 |
| SUSE:Manager Proxy Module 4.1 | mgr-osad | before 4.1.5-2.9.4 | 4.1.5-2.9.4 |
| SUSE:Manager Proxy Module 4.1 | rhnlib | before 4.1.3-4.3.2 | 4.1.3-4.3.2 |
| SUSE:Manager Proxy Module 4.1 | spacewalk-backend | before 4.1.21-4.22.7 | 4.1.21-4.22.7 |
| SUSE:Manager Proxy Module 4.1 | spacewalk-client-tools | before 4.1.9-4.12.4 | 4.1.9-4.12.4 |
| SUSE:Manager Proxy Module 4.1 | spacewalk-proxy | before 4.1.4-3.9.4 | 4.1.4-3.9.4 |
| SUSE:Manager Proxy Module 4.1 | spacewalk-proxy-installer | before 4.1.6-3.3.2 | 4.1.6-3.3.2 |
| SUSE:Manager Proxy Module 4.1 | spacewalk-web | before 4.1.23-3.18.6 | 4.1.23-3.18.6 |
| SUSE:Manager Server Module 4.1 | cobbler | before 3.0.0+git20190806.32c4bae0-5.6.4 | 3.0.0+git20190806.32c4bae0-5.6.4 |
| SUSE:Manager Server Module 4.1 | grafana-formula | before 0.4.0-3.6.2 | 0.4.0-3.6.2 |
| SUSE:Manager Server Module 4.1 | mgr-libmod | before 4.1.7-3.16.2 | 4.1.7-3.16.2 |
| SUSE:Manager Server Module 4.1 | prometheus-exporters-formula | before 0.9.0-3.19.2 | 0.9.0-3.19.2 |
| SUSE:Manager Server Module 4.1 | prometheus-formula | before 0.3.1-3.6.2 | 0.3.1-3.6.2 |
| SUSE:Manager Server Module 4.1 | py26-compat-salt | before 2016.11.10-6.11.2 | 2016.11.10-6.11.2 |
| SUSE:Manager Server Module 4.1 | smdba | before 1.7.8-0.3.6.2 | 1.7.8-0.3.6.2 |
| SUSE:Manager Server Module 4.1 | spacewalk-config | before 4.1.5-3.3.2 | 4.1.5-3.3.2 |
| SUSE:Manager Server Module 4.1 | spacewalk-java | before 4.1.30-3.31.7 | 4.1.30-3.31.7 |
| SUSE:Manager Server Module 4.1 | spacewalk-utils | before 4.1.14-3.12.2 | 4.1.14-3.12.2 |
+8
Same product
xstream: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-39144XStream is vulnerable to a Remote Command Execution attackKEV93Now
- CVE-2019-10173It was found that xstream API version 1.4.10 before 1.4.11 introduced a regression for a previous deserialization flaw.68This week
- CVE-2013-7285Xstream API versions up to 1.4.6 and version 1.4.10, if the security framework has not been initialized, may allow a remote attacker to run 64This week
Published before and after this one in the same product
- ← EarlierCVE-2017-7957Apr 29, 2017 · XStream through 1.4.9, when a certain denyTypes workaround is not used, mishandles attempts to create an instance of the primitive type 'voi31Monitor
- ← EarlierCVE-2020-26217Nov 16, 2020 · Remote Code Execution in XStream61This week
- Later →CVE-2020-26259Dec 16, 2020 · XStream is vulnerable to an Arbitrary File Deletion on the local host when unmarshalling52Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:libxstream-java | 1.4.15-1 · Debian:12 | Package registry (OSV) |
| Maven:com.thoughtworks.xstream:xstream | 1.4.15 | Package registry (OSV) |
| opensuse:xstream | 1.4.15-lp152.2.3.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| suse:cobbler | 3.0.0+git20190806.32c4bae0-5.6.4 · SUSE:Manager Server Module 4.1 | Package registry (OSV) |
| suse:grafana-formula | 0.4.0-3.6.2 · SUSE:Manager Server Module 4.1 | Package registry (OSV) |
| suse:mgr-libmod | 4.1.7-3.16.2 · SUSE:Manager Server Module 4.1 | Package registry (OSV) |
| suse:mgr-osad | 4.1.5-2.9.4 · SUSE:Manager Proxy Module 4.1 | Package registry (OSV) |
| suse:prometheus-exporters-formula | 0.9.0-3.19.2 · SUSE:Manager Server Module 4.1 | Package registry (OSV) |
| suse:rhnlib | 4.1.3-4.3.2 · SUSE:Manager Proxy Module 4.1 | Package registry (OSV) |
| suse:spacewalk-backend | 4.1.21-4.22.7 · SUSE:Manager Proxy Module 4.1 | Package registry (OSV) |
| suse:spacewalk-client-tools | 4.1.9-4.12.4 · SUSE:Manager Proxy Module 4.1 | Package registry (OSV) |
| suse:spacewalk-proxy | 4.1.4-3.9.4 · SUSE:Manager Proxy Module 4.1 | Package registry (OSV) |
| suse:spacewalk-proxy-installer | 4.1.6-3.3.2 · SUSE:Manager Proxy Module 4.1 | Package registry (OSV) |
| suse:spacewalk-web | 4.1.23-3.18.6 · SUSE:Manager Proxy Module 4.1 | Package registry (OSV) |
| suse:xstream | 1.4.15-3.3.2 · SUSE:Linux Enterprise Module for Development Tools 15 SP2 | Package registry (OSV) |
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Nuclei detection template ×1
- Proof-of-concept repository on GitHub ×2
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Nuclei detection template | Nuclei template CVE-2020-26258 | — |
| Proof-of-concept repository on GitHub | stars:0 | 2021-01-22 |
| Proof-of-concept repository on GitHub | stars:0 | 2025-07-11 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- First PoC+37 d
- TodayOct 20, 2026+2134 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-21-0989 · Dec 13, 2021(IBM Güvenlik Bildirimi)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- none
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-918 · Server-Side Request Forgery (SSRF)CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- SSVC exploitation— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (12 more)Show less
- lists.apache.org/thread.html/r97993e3d78e1f5389b7b172ba9f308440830ce5f051ee62714a0aa34@%3Ccommits.struts.apache.org%3E
- lists.debian.org/debian-lts-announce/2020/12/msg00042.html
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB
- security.netapp.com/advisory/ntap-20210409-0005
- www.debian.org/security/2021/dsa-4828
- lists.apache.org/thread.html/r97993e3d78e1f5389b7b172ba9f308440830ce5f051ee62714a0aa34%40%3Ccommits.struts.apache.org%3E
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB/
- security.netapp.com/advisory/ntap-20210409-0005/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.